On 2015 Sep 16, Geriatric Medicine Journal Club commented:

The related study (Delayed-start analysis: Mild Alzheimer's disease patients in solanezumab trials, 3.5 years. Alzheimer's & Dementia: Translational Research & Clinical Interventions. In press. 2015) was critically appraised at the August 2015 Geriatric Medicine Journal Club (follow #GeriMedJC on Twitter). The full discussion can be found at: http://gerimedjc.blogspot.com/2015/09/study-author-joins-us-for-successful.html?spref=tw This is an interesting study design, but the hype around the results may be disproportionate or premature to the magnitude of clinically meaningful benefit shown.

On 2015 Mar 18, Peter Hajek commented:

The title is misleading. An association does not prove causation.

On 2016 Apr 06, Daniel Tsin commented:

Correction in reference 1. Tsin DA, Sequeria RJ, Giannikas G. Culdolaparoscopic cholecystectomy during vaginal hysterectomy. JSLS. 2003 Apr-Jun;7(2):171-2. PMID 12856851

On 2016 Jun 01, Kenneth Witwer commented:

It is reported that "miR-150 mRNA and protein expression levels" were assayed in this study, but miR-150, a 22-nucleotide RNA, is neither a messenger RNA nor a protein. The reverse transcription and RT-PCR steps described in the methods could not have amplified a microRNA specifically. Furthermore, both Western blots and immunohistochemistry images are shown and said to have been obtained with a "mouse polyclonal anti-miR-150 antibody." The target is repeatedly referred to as a protein, reducing the likelihood that typographical errors or translation issues interfered with reporting. Additional methodologic details would be helpful in resolving these problems, including primer sequences and the actual protein target and source of the antibody.

On 2015 Jul 10, Matthew Shirley commented:

I would just like to point out that the axes in Figure2 panels A & B should probably range from 0.1-1.0 and not 0.1-0.1.

On 2015 Apr 22, Thomas Heston commented:

Compared with the functional testing group, those undergoing an initial CT angiogram were 50% more likely to undergo catheterization (12.2% vs 8.1%) and almost twice as likely to undergo revascularization (6.2% vs 3.2%). These additional procedures, however, did not show any clinical benefit during a median follow-up period of 25 months, as measured by the primary outcome measure (3.3% in the CTA group vs 3.0% in the functional testing group). Thus, the obvious conclusion seems to be that CTA results in more radiation, more catheterizations, and more revascularizations --- without any improvement in clinical outcomes. The results from this study suggest that functional testing is the best initial noninvasive test in symptomatic patients with suspected coronary artery disease.

On 2015 Sep 16, Geriatric Medicine Journal Club commented:

This study aims to look at a multicomponent intervention to prevent cognitive decline in at-risk elderly. This article was critically appraised at the July 2015 Geriatric Medicine Journal Club (follow #GeriMedJC on Twitter). The full discussion can be found at: http://embed.symplur.com/twitter/transcript?hashtag=GeriMedJC&fdate=07/31/2015&shour=00&smin=00&tdate=08/01/2015&thour=00&tmin=00

On 2016 Apr 25, Johannes M Dijkstra commented:

The title of this article "CXCR3 chemokine receptor enables local CD8(+) T cell migration" is not substantiated by the experimental data, because increased presence of the CD8(+) T cells in the infected cell area may be explained by increased binding.

Although not immediately clear to readers, the article is mostly about a time window effect at days 5-7 after infection. Important observations for the virus titers on those days should be shown if Fig. 3F, in which the data for the day 5 p.i. result are contradictory to the story. That figure is either an error, or needs serious discussion.

Previously, I have posted these comments plus a few additional minor ones on the Immunity site below the article, but the authors did not respond, and Immunity made the comments close to invisible. Then I placed my comments as a correspondence article on F1000Research, where the advantage is that independent third parties can have their say as reviewers. For more explanation of the above points, please see that web-site http://f1000research.com/articles/4-922/v1 .

However, the F1000Research system requires two reviewers before the publication can proceed, and I only managed to find one reviewer within the relevant research field. The one reviewer, Dr. J.R. Groom, as I interpret her words, agreed with me that Fig. 3F requires an explanation by the authors, but feels that the text by Hickman et al. on the migration versus binding issue is more nuanced than I portray it in my criticism. Her comments can be read in detail at http://f1000research.com/articles/4-922/v1 . Although I do agree with her that within the Hickman et al. text some nuances can be found, that does not take away that they boldly and in my opinion without substantiation concluded a migration enabling effect in the title and that most readers will understand the wordings by Hickman et al. similar to as reflected in Fig. 1 of the corresponding preview article by Beura and Masopust http://www.cell.com/immunity/fulltext/S1074-7613(15)00095-3 .

Both Dr. Groom and I agree that the technical part of the experiments in the Hickman et al. article is mostly sound.

On 2015 May 15, M Felix Freshwater commented:

Although not called a systematic review, in fact it was one for two obvious reasons: 1. Systematic reviews are defined by Cochrane as analyses of articles with “a clearly stated set of objectives with pre-defined eligibility criteria for studies”. The authors’ stated objective was “to identify the most highly cited microsurgery articles”, and the authors’ pre-defined eligibility criteria included articles that appeared in five high-impact peer-reviewed journals. 2. It was assigned a Level of evidence III. Using the ASPS level of evidence system a level III is a systematic review of retrospective cohort or comparative study; case-control studies; or while according to 2009 OCEBM level 3 is a systematic review of case control studies.<br />This review does not meet the minimum standards on how a proper systematic review should be reported that were codified in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and published in 2009.<br> Item 10 of PRISMA’s checklist describes the proper methodology for validating extracted data: “Describe … any processes for … confirming data from investigators.” The authors did not describe how they confirmed that their data extraction was accurate. AMSTAR, a validated checklist for measuring the quality of systematic reviews states: “There should be at least two independent data extractors and a consensus procedure for disagreements should be in place.” This review contains erroneous data, which may be a result of not reading the original papers and/or of not complying with PRISMA. One obvious example is the misidentification of the country of origin of the most highly cited clinical article. While the review stated that the country of origin was the United Kingdom, the paper itself never uses the phrase “United Kingdom” and clearly identifies its country of origin as Australia on its first and final pages. As this review deemed it worthy to analyze papers by country, any results and conclusions based upon country of origin are suspect. Without duplicating the study, it is impossible for any reader to know which other data in this review are flawed. This review provides an educational opportunity, as it affords the editors and peer reviewers to join other journals that publish papers on microsurgery including Annals of Plastic Surgery, Journal of Plastic, Reconstructive & Aesthetic Surgery, Journal of Hand Surgery (Am) and Journal of Hand Surgery (Euro), which have adopted PRISMA as a requirement when reporting systematic reviews. I suggest that the editor, who also is a co-author of this paper, enforce the use of PRISMA in order to lessen the possibility of future errors arising from inaccurate data extraction.

On 2017 Mar 03, Matthew Speir commented:

To add on to what Kim Pruitt said in her comment, our previous "RefSeq Genes" track was not equivalent to what was provided by RefSeq. It was based on the realignment of their provided RNAs to the genome.

However, we recently released an "NCBI RefSeq" track that is based entirely on coordinates and alignments provided by the RefSeq group. You can read about it more on our website: https://genome.ucsc.edu/goldenPath/newsarch.html#030317.

On 2015 Mar 18, Kim D Pruitt commented:

As the head of NCBI’s RefSeq project I would like to make a clarification on the relevance of the authors' results to RefSeq. The authors refer to the RefSeq dataset and UCSC RefGene dataset as if they are equivalent. However, the RefGene data represents annotation derived from UCSC-generated alignments of approximately 1/3 of the RefSeq data. The analysis presented here is of the UCSC RefGene dataset and not the complete RefSeq set as obtained at NCBI which builds and curates RefSeq. NCBI also provides human genome annotation data that includes the comprehensive RefSeq transcript data set. Details about the annotated location of a given RefSeq transcript at NCBI may differ from that shown in the UCSC RefGene track.

Therefore, the relevance of this analysis to RefSeq is unclear.

On 2015 Mar 28, Markus Meissner commented:

Hi Juergen, Fully agree ! Will be great to see what happens when interactions are rapidly disrupted. This is one of the main caveats of current conditional systems....simply too slow for fast processes, such as gliding and invasion.

On 2015 Mar 24, Jürgen Bosch commented:

Thank you Markus for your positive feedback on our review. I think it will be crucial in the future to utilize chemical probes to study these invasion mechanisms in different parasites.

On 2015 Mar 18, Markus Meissner commented:

This is a very nice review by Boucher and Bosch, summarising our current knowledge of apicomplexan invasion pathways. In the first part of the review the authors focus on novel structural data of the individual complexes known to be involved in gliding motility and invasion, while in the second part the current data regarding potential, alternative invasion pathways are presented. While the authors favour the more “traditional” linear motor system, data from diverse groups have been openly discussed, although some of the arguments might need further clarification. For example, the authors do not mention one important feature of the GAP45-depleted parasites. In these parasites the integrity of the IMC is lost AND other motor components dissociate and mislocalise to the cytosol of the parasite. Yet, these parasites are still capable of moving and invading, although the anchorage for the motor complex is missing. In case of act1KO it is in our opinion unlikely that parasites still have sufficient actin for gliding motility and invasion yet not for egress or apicoplast replication. Furthermore, the controversy regarding the effect of CytoD on host or parasite actin (see Rynig and Remington, 1978; Dobrowolski et al., 1996; Gonzales et al., 2009) and recent data on the role of aldolase ( Shen et al., 2014 ) seriously undermine the original rationale for the linear motor model, and in our view suggest that the earlier data supporting the model should be treated with as much scrutiny as the recent data arguing against it.<br> I agree with the authors that findings in Toxoplasma cannot necessarily be directly transferred to Plasmodium. However, this is also the case for other apicomplexans, which have undoubtly different (or alternative) invasion mechanisms, such as Theileria or Cryptosporidium. Of note, Theileria has a well conserved AMA1, but doesn't form a tight junction. While Theileria might use AMA1 for “zippering” into the host cell, it doesn’t use it for force transmission, since invasion is independent of host AND parasite actin (Shaw, 1999). More experiments are required to make sense out of these sometimes conflicting data, which can at this point be interpreted in multiple ways, and we fully agree with the authors that we need an open, unbiased discussion in order to solve the puzzle.

On 2016 Jun 03, Lydia Maniatis commented:

The authors of this article perform a useful service: They experimentally falsify a claim that currently enjoys some favor. Falsifying (false) assumptions is a fundamental activity in science; a science incapable of rejecting false views is incapable of selecting true(er) ones, and thus incapable of progress.

This simple fact is so antithetical to the current “don't criticize” ethos in vision science that the authors have (either by choice or editorial demand) been forced to bury the lead and accentuate the mildly positive and/or vague. Thus the title of the article is vague, implying nothing and the abstract reports a mixed salad of findings. For a statement of any conclusions we're directed to the article itself.

From the intro, we learn that Christou and Koenderink (1997) have speculated that the presence of smooth occlusions is a key factor in seeing “shape-from-shading.” Amazingly, in the nearly 20 years since, no one – including its originators - has actually tested this claim. After explaining what a “reasonable” suggestion this is, Todd and Egan note that “virtually all past studies have included visible smooth contours.” So they propose to put this suggestion to a real test, but aren't allowed to state it this strongly so near the beginning of the article; they are merely going to “further examine” the issue.

The discussion also drags its feet in getting to the point, since the first thing we learn is that “One of the basic findings of the present investigation is that observers’ perceptions of 3-D shape from shading are sheared slightly toward the direction of illumination. This phenomenon was first discovered by Koenderink et al. (1996a, 1996b) and Christou and Koenderink (1997).” (The “phenomenon” is context-specific, since perceptions of 3D shape will certainly not always be sheared in the direction of illumination – it will depend on the shapes. All that can be said is that this sometimes happens).

Finally, we get to the point: “[Christou & Koenderink, 1997] speculated that the [high degree of] constancy was most likely due to information provided by visible smooth occlusion contours. The present investigation WAS DESIGNED SPECIFICALLY TO TEST THAT SUGGESTION, and the RESULTS SHOW CLEARLY that the absence of smooth occlusions in the masked conditions had a NEGLIGIBLE IMPACT [all caps mine] on the overall pattern of performance.”

So Christou and Koenderink's purportedly “reasonable” suggestion is apparently false. That's the point, and the authors shouldn't have been forced (or internalized a reequirement) to pussyfoot around it. They should have stated it as clearly up front as they do (eventually) in their discussion.

Falsification of FALSE theories is how science proceeds, and you can't show they're false unless you actually target specific assumptions for testing. Of course, proponents of the idea may, if they'd like, and can, make counterarguments.

So kudos to the authors for directly testing the claim, as they did in a previous article on an another ad hoc suggestion. Next time, I hope they adopt a more direct reporting style as well.

But on theory, there's more to be said, starting with https://pubpeer.com/publications/1220D804D501BB15474B6D0F33FC7D

On 2015 Aug 20, Lydia Maniatis commented:

The authors here report having “investigated how texture and stereo cues are integrated to perceive 3D slant.” The problem here (as with other literature dealing with the same topic) is with the unqualified references to “texture cues.”

2D “textures” are composed of 2D shapes, and 2D shape is dispositive when it comes to the perception of slant. If I start with a rectangle (or syncytium of rectangles) and I slant it so that it produces a trapezoidal 2D projection, then this projection will look like a slanted rectangle. If I start with a trapezoid and slant it so that it casts a rectangular 2D projection, then it will look like a fronto-parallel rectangle, not a slanted trapezoid. Perceived slant is a function of the shape of the projection.

Because shape is the key factor mediating apparent slant, and because textures are composed of shapes, saying that we will study the role of “texture” without specifying and controlling for the effects of the particular shapes of which the texture is composed is like proposing to investigate the role of “food cues” on blood pressure, without caring about what type of food we are employing as our “stimulus.” Such practice ensures the enduring confusion and ambiguity that characterizes slant studies, which often seem to contradict each other.

This study used “Voronoi” textures. Why? An earlier study (Todd et al, 2010) used textures composed of rectangles orthographically projected. Yet another study referred to by Saunders and Chen used Voronoi textures that were more regular than theirs. Do the authors believe that by using the type of structure the do, in which the cells' shape varies, and which has a particular degree of irregularity, they are controlling for the effects of shape? To continue my previous analogy, this would be like assuming that mixing many foods together will control for the effect of the individual nutrients on blood pressure.

If we know a variable matters, then we don't control for it by mixing it up its values, we control for it by controlling for it. “Food” in this analogy is obviously not an appropriate level of analysis, and the results will vary with the choice of “food.” The same goes for “texture.” What is left after we subtract shape? At the least, the authors should have provided some rationale for their choice of texture.

There is no doubt whatsoever that the choice of “texture” affects perceived slant. Erkelens (2013) used a “texture” composed of rectangles under perspective projection and found very good agreement with prediction, and an underestimation at all slants. Saunders and Chen found underestimation at low slants, and not at higher ones. They should explain why this low/high dichotomy should be found in their particular conditions, including their choice of pattern, and not in, e.g., Erkelens'. (Are they suggesting that by using “Voronoi” patterns, they have isolated the role of “texture,” independently of shape, and that their results are more valid?)

The authors' decision to deal with the potential role of the outline containing their texture by randomly varying this shape reflects the tendency to embed confounds in the data in the hope that they will average out (rather than distort or flatten the results – averaging black and white makes grey) rather than to confront and control for them head on.

Of course, they found that “texture” cues and disparity cues are somehow integrated (the claim that they are “optimally” integrated is difficult to judge, as it has been preceded by layers of speculation). The basic findings were a sure thing. The specifics of the data are uninterpretable due to lack of control of relevant variables.

On 2015 Apr 24, CHARLES KING commented:

I feel there is a serious methodological flaw in the recently published Cochrane Review “Circulating antigen tests and urine reagent strips for diagnosis of active schistosomiasis in endemic areas” by Ochodo, et el., 2015. The inaccurate analysis used in the HSROC estimation skews the reported summary results on the diagnostic performance of both antigen tests and dipsticks, and a correct analysis would actually invalidate several of the conclusions and recommendations found in the current version of the review: My objection is to the use of egg count diagnostics as a reference standard for the diagnosis of Schistosoma infection. The stool egg count for S. mansoni and S. japonicum and the urine filtration egg count for S. haematobium have long been known to be poorly sensitive for low intensity infections. When subjects are repeatedly tested for 7-15 days in a row, single day egg count testing has a sensitivity of 40-60%. Although these imperfect tests remain in widespread use in field studies and control campaigns because they accurately detect persons with heavy infections, they cannot be relied upon to establish infection in all subjects. The failings of stool counting for S. mansoni were documented in the work of de Vlas and colleagues cited below [1,2]. The limitations of stool counting for S. japonicum have been established by Carabin, et al.,[3] and Hubbard, et al.,[4] and the limitations of egg counting for S. haematobium can be found in Savioli et al.,[5] and Warren, et al.[6]

In all cases, egg counting cannot be considered a ‘gold standard’ diagnostic. Such a test, with ~50% sensitivity, is so inaccurate to be useless on a per-individual diagnostic basis. I feel that the appropriate comparison for the Ochodo, et al., review would have been Latent Class Analysis, in which two imperfect tests are compared in their attempt to classify an unmeasured ‘true’ infection status. Using egg count results as a reference standard in the HSROC was a serious error--reporting a new test’s performance benchmarked against an already flawed test is meaningless, and in fact, the reported comparisons are misleading to the practitioner or public health officer.

Secondly, I feel that the exclusion of results from populations or areas without significant Schistosoma risk was also a tactical error. If we are concerned about the specificity of new tests, there is great value in measuring results among persons who have a very low prior probability of infection.

I would strongly recommend that the Cochrane review be revised and re-issued after the authors revisit the data using the approach of Dendukuri, et al., 2012 [7] for situations where there is no gold standard. Their SAS code is available online, and the reanalysis could be done in a matter of a day. The Bayesian LCA should be informed by prior observations on the estimated specificity of single (or treble stool) examinations, and the known specificity estimates of dipsticks and antigen testing among non-endemic populations.

The concern is that while the authors discuss and reiterate the lack of a gold standard and the insensitivity of the egg count procedures they go right ahead and use them as their comparator and they present strong conclusions that are biased by their approach. This will only add to policymakers’ confusion about the utility of these alternative test approaches.

By way of disclosure, I have no relation to the manufacturers of these tests, and I have no conflict of interest in this matter.

1. de Vlas SJ, Engels D, Rabello AL, Oostburg BF, Van Lieshout L, Polderman AM, Van Oortmarssen GJ, Habbema JD, Gryseels B, 1997. Validation of a chart to estimate true Schistosoma mansoni prevalences from simple egg counts. Parasitology 114 ( Pt 2): 113-21.
2. de Vlas SJ, Gryseels B, 1992. Underestimation of Schistosoma mansoni prevalences. Parasitol Today 8: 274-277.
3. Carabin H, Marshall CM, Joseph L, Riley S, Olveda R, McGarvey ST, 2005. Estimating the intensity of infection with Schistosoma japonicum in villagers of Leyte, Philippines. Part I: A Bayesian cumulative logit model. The Schistosomiasis Transmission & Ecology Project (STEP). Am J Trop Med Hyg 72: 745-753.
4. Hubbard A, Liang S, Maszle D, Qiu D, Gu X, Spear RC, 2002. Estimating the distribution of worm burden and egg excretion of Schistosoma japonicum by risk group in Sichuan Province, China. Parasitology 125: 221-31.
5. Savioli L, Hatz C, Dixon H, Kisumku UM, Mott KE, 1990. Control of morbidity due to Schistosoma haematobium on Pemba Island: egg excretion and hematuria as indicators of infection. Am J Trop Med Hyg 43: 289-295.
6. Warren KS, Arap Siongok TK, Hauser HB, Ouma JH, Peters PAS, 1978. Quantification of infection with Schistosoma haematobium in relation to epidemiology and selective population chemotherapy. I. Minimal number of daily egg counts in urine necessary to establish intensity of infection. Journal of Infectious Diseases 138: 849-55.
7. Dendukuri N, Schiller I, Joseph L, Pai M, 2012. Bayesian meta-analysis of the accuracy of a test for tuberculous pleuritis in the absence of a gold standard reference. Biometrics 68: 1285-1293.

On 2015 Jun 29, Bill Cayley commented:

A good example of when "Less" may be "more": https://lessismoreebm.wordpress.com/2015/05/15/surgical-vs-nonsurgical-treatment-of-adults-with-displaced-fractures-of-the-proximal-humerus-the-profher-randomized-clinical-trial/

On 2015 Mar 11, Alexis Clapin commented:

Congratulation for your work.

I would like to draw your attention on one of the four selected studies: MSCRG 1999 study(1). This study compared whole brain atrophy in relapsing-remitting MS patients treated with either Avonex or a placebo. One hundred forty patients are selected for this comparison. These patients participated to the initial MSCRG 1996 study (2), which was stopped earlier than planned. Among the 301 patients included, 172 were followed up for two years. The 140 patients are thus drawn from these 172 patients.

When reviewing the MSCRG 1996 study, the FDA analysed the efficacy of Avonex on the relapse rate for different subgroups of patients to check if, as Biogen said, there was a lag time between initiation of treatment and onset of clinical benefit. FDA reviewers demonstrated (3)that there was no lag time but that patients followed up for two years were different from those followed up for less than two years. During the first year of the study, Avonex patients followed up for less than two years experienced a +29% increase of the relapse rate versus placebo while patients followed up for at least two years experienced a -29% decrease versus placebo. During the second year, relapse rate did not change (-32%). FDA finally concluded that patients followed for two years were different from those followed up for less than two years, but did not provide a comparison of the subgroups.

The group of patients followed up for two years is thus a very odd subgroup of the randomised patients in the initial MSCRG 1996 study (2); obviously there are favouring the positive evaluation of the product.

For further explanation of the bias in the MSCRG 1996 study, you can see this analysis (4) on the MSCRG 1996 study (2).

The Cochrane collaboration recently considered that Avonex had a negative benefit/risk ratio (5). Their risk of bias analysis for the MSCRG (1996) (2) is more negative than the one you provide for the MSCRG 1999 study (1). To conclude, I am not sure that you can consider MSCRG 1999 (2) patients study as an unbiased subgroup of the initial MSCRG 1996 study (1). It is just a comparison of a group of best responders to Avonex to a group of worst responders to placebo.

(1)http://www.ncbi.nlm.nih.gov/pubmed/10563615 (2)http://www.ncbi.nlm.nih.gov/pubmed/8602746<br> (3)http://www.fda.gov/downloads/Drugs/DevelopmentApprovalProcess/HowDrugsareDevelopedandApproved/ApprovalApplications/TherapeuticBiologicApplications/ucm086056.pdf (4)http://www.ncbi.nlm.nih.gov/pubmed/23662092<br> (5)http://www.ncbi.nlm.nih.gov/pubmed/23744561

On 2015 Jul 10, Matthew Shirley commented:

I won't discount the utility of writing your own software to solve a problem, but I do take issue with the fact that this application note does not mention (reference) except in supplement #1 the existence of existing mature tools that accomplish much of what VASP aims to provide. The authors also do not clearly state what about the software is novel or better that these existing tools (only that it "makes no assumptions regarding the underlying disease transmission mechanism", which other programs arguably allow by integrating the results from multiple parameterized runs?). To be clear, I do not think these are reasons to prevent publication or development of this program - I just find the presentation of the research results a bit misleading.

On 2016 Jun 06, Dr, Stanley Goldberg commented:

Why would you transect the internal sphincter routinely when you only have to do it in a small proportion of the patients when the intra-sphincteric fistula persists?

On 2015 May 04, Christopher Southan commented:

Good paper, see http://cdsouthan.blogspot.se/2015/05/antimalarial-dot-joining-for-mmv008138.html for database mapping of compounds

On 2017 Mar 25, Gerhard Holt commented:

Eliminating S.A.S.P. cells : Targeting Senescence Specific Surface Antigens

with CAR-T cells, mAbs or Minicells ?

                                           by Gerhard Holt

Research into cellular aging and the Senescence-Associated Secretory Phenotype indicates that selective elimination of senescent cells may provide substantial benefits - potentially including increases in healthspan.[1]

Many surface antigens may be differentially expressed on senescent/SASP cells relative to non-senescent cells. Ideally, the chosen cell surface antigen(s) would be highly specific to senescent/SASP cells to reduce collateral damage to non-senescent cells. For example, EFNB1 and/or EFNB3 may be appealing targets.[1]

These "Senescence Specific Surface Antigen" targets might - if necessary - include potentially spurious surface antigens that may have negligible causal relation to SASP but are nevertheless fairly specific. One could presumably also target multiple "SSSA"s to achieve better coverage.

Several methods to target cells expressing these SSSA's might be used - including :

(1) CAR-T cells vs the antigen(s). [2]

Pros :

Extensive removal of target cells. Long lasting surveillance against subsequent reemergence of the senescent/SASP cells with those surface antigens.

Cons :

May cause collateral damage or impair other important functions (for example - potentially - wound healing).

Questions :

Could one potentially embed a switchable "suicide gene" in the CAR-T cells, or perhaps a reversible switch to transiently deactivate the CAR-Ts either systemically or locally?

Could one also embed a highly specific artificial set of inducible surface antigens on the CAR-Ts to facilitate subsequent removal or modification by mAbs or minicells (see below)?[3]

(In the longer term one might also potentially examine logic-gated CAR-T cell approaches for increased specificity, or to target the absence of a surface antigen that is differentially expressed on Non-senescent cells ? [3])

(2) mAbs vs the antigen(s).

Pro :

Well established approach.

Con :

No longer term surveillance.

(3) Minicells vs the antigen(s). [4]

Pros :

Highly specific targeting. Minicells could also be targeted to multiple different SSSA's.

Can specifically carry cytotoxic medications to the target cells.

Can add siRNAs to the minicells to perform more subtle intracellular actions (perhaps inducing apoptosis, reversing (or accelerating) aberrant intracellular processes, attracting CAR-T cells, or modifying natural immune responses to the cell, or expressing alternative surface antigens).

Could be used in addition to CAR-T approaches, or perhaps as a backup to help selectively deactivate CAR-T cells if responses cause excessive collateral damage or if one needs to (perhaps temporarily) damp the response.

Con :

No long term surveillance.

Conclusion :

Targeting senescence specific surface antigens may be a useful way to selectively destroy senescent/SASP cells.

The application of CAR-T cell, mAb, and minicell approaches might be effective in this task, and will hopefully be the subject of further research.

REFERENCES :

[1] Zhu, Y. Tchkonia, T. et al. (2015) The Achilles' heel of senescent cells: from transcriptome to senolytic drugs. Aging Cell. 2015 Aug;14(4):644-58. doi: 10.1111/acel.12344. Epub 2015 Apr 22.

www.ncbi.nlm.nih.gov/pubmed/25754370

[2] Kochenderfer JN et al. (2010) Adoptive transfer of syngeneic T cells transduced with a chimeric antigen receptor that recognizes murine CD19 can eradicate lymphoma and normal B cells. Blood. 2010 Nov 11;116(19):3875-86. doi: 10.1182/blood-2010-01-265041. Epub 2010 Jul 14.

www.bloodjournal.org/content/bloodjournal/116/19/3875.full.pdf

[3] Roybal, K.T., et al. (2016). Precision tumor recognition by T cells with combinatorial antigen-sensing circuits. Cell 164, 770–779. dx.doi.org/10.1016/j.cell.2016.01.011

www.sciencedirect.com/science/article/pii/S0092867416000519

[4] MacDiarmid, J.A. et al. (2009) Sequential treatment of drug-resistant tumors with targeted minicells containing siRNA or a cytotoxic drug. Nat. Biotechnol. 27, 643–651.

www.nature.com/nbt/journal/v27/n7/pdf/nbt.1547.pdf

On 2017 Jan 13, Yuwei Fan commented:

How could VITA Enamic contain "high amount of Al2O3 (approximately 23 wt%)"? There is no actual alumina phase in Enamic. A very misleading article.

On 2017 Apr 20, Richard L Harvey commented:

Yes, the electrode was placed ipsilesionally and localized using stereotaxic techniques based on perilesional fMRI signal during affected hand movement tasks.

On 2017 Apr 18, Lawrence Moon commented:

Does this report mention where stimulation was performed? Based on the Harvey et al paper previously I'm assuming it's ipsilesional to infarct.

On 2015 Mar 11, David Mage commented:

This comment was written from reading this abstract the instant it was uploaded before the link to the pdf was added by PUBMED. A final comment is added at the end as a CODA that was made necessary when the article was read. The medical literature has at this instant of writing 10778 PUBMED returns for SIDS (some are not on sudden infant death syndrome but with the same acronym). Most of them are worthless shots-in-the-dark hoping to hit something. The burgeoning literature has an insatiable demand for content and editors and reviewers are not guarding the gates, as true experts cannot review every article submitted in their fields before publication. Hundreds of articles are written on small sample size studies that report a glimmer of a correlation of SIDS with something that they hope by some undiscovered alchemical legerdemain can be converted into a causation. And yet, as the sample size increases the vision of gold always becomes one of pyrites. Its like the fisherman hooking something big leading to visions of a record size catch, only to find when it breaks the surface that it is an old tire. Temperature is involved with SIDS but in the completely opposite direction. SIDS rate maximizes in the winter, not in the summer. Hawaii, a state without seasons, (O.K., maybe beautiful weather and very beautiful weather) has a maximum SIDS rate in the Northern hemisphere winter (Mage DT, 2004) that we relate to the higher incidence of respiratory infection in Japan and the continental U.S. by a tourist infection vector (Mage DT, 2009). This writer served with the WHO and spent 3.5 years in Malaysia where the tropical seasonal heat and humidity on a normal day would put Montreal to shame on its hottest and most humid day. O.K. now lets look at Canada (Mage DT, 2005). For years 1985-89 and 1994-1998 there were in all of Canada during the winter (Jan-Mar) 504 SIDS and 368 SIDS in the summer (Jul-Sep). Oh high temperature, where is thy sting? CODA: The authors wrote perceptively a la Trofim Desinovich Lysenko - "Another issue is that Taiwan has a mild climate with a population accustomed to heat, which may mitigate the impact of temperature on SIDS." Ah yes, the parental accomodation to heat by living in semi-tropical Taiwan is passed on through their mutated-genes to their offspring who at birth have their parent's ability to withstand the fearsome heat waves uniquely endemic to Taiwan.

On 2015 Jul 25, Kamaldeep Bhui commented:

see also: Health Technol Assess. 2015 Apr;19(31):vii-xxiv, 1-173. doi: 10.3310/hta19310.

If you're interested in this paper, see also:

Interventions designed to improve therapeutic communications between black and minority ethnic people and professionals working in psychiatric services: a systematic review of the evidence for their effectiveness.

Bhui K(1), Aslam RW(1), Palinski A(1), McCabe R(1), Johnson MR(2), Weich S(3), Singh SP(3), Knapp M(4), Ardino V(4), Szczepura A(3).

We need more debate and research on the components of interventions to improve therapeutic communications, and engage socially excluded or hard to reach populations.

On 2015 Jul 25, Kamaldeep Bhui commented:

The affiliation for Bhui and the host institution in this publication is incorrect. It should be Queen Mary University of London, and not Swansea University which is the affiliation for Dr Ahmed.

On 2015 Dec 11, Mark Johnston commented:

An interactive protocol from this article is freely available at protocols.io.

On 2015 Mar 19, David Keller commented:

High-dose Coenzyme Q10 was safe in the Parkinson Study Group trial

In their reply to my letter [1] pointing out that the doses of Coenzyme Q10 tested may have been too small to treat statin-induced myopathy, Banach and Mikhailidis state: "Another question is whether higher dosages of CoQ10 have adverse effects. Contemporary data concerning the administration of CoQ10 at dosages higher than 1200 mg/d are limited" [2].

To address these safety concerns, consider the Parkinson Study Group's trial of high-dose CoQ10; 600 subjects with early Parkinson disease were randomized to placebo or to high-dose CoQ10. 94 subjects received placebo, 87 received 1200 mg/d of CoQ10, and 86 received 2400 mg/d of CoQ10 [3]. Only 65 participants withdrew prematurely: 29 who received placebo, 19 who received 1200 mg/d of CoQ10, and 17 who received 2400 mg/d of CoQ10, and it was reported that "treatments were well tolerated with no safety concerns".

While it was disappointing that high-dose Coenzyme Q10 did not slow the progression of Parkinson's disease, at least we learned that doses of up to 2400 mg per day seem to be safe and well-tolerated.

References

1: Keller DL. Coenzyme Q10 and statin-induced myopathy--I. Mayo Clin Proc. 2015 Mar;90(3):419-20. doi: 10.1016/j.mayocp.2015.01.006. PubMed PMID: 25744125.

2: Banach M, Mikhailidis DP; Lipid and Blood Pressure Meta-analysis Collaboration (LBPMC) Group. In reply-Coenzyme Q10 and Statin-Induced Myopathy. Mayo Clin Proc. 2015 Mar;90(3):420-1. doi: 10.1016/j.mayocp.2015.01.003. PubMed PMID: 25744127.

3: Parkinson Study Group QE3 Investigators, A randomized clinical trial of high-dosage coenzyme Q10 in early Parkinson disease: no evidence of benefit. JAMA Neurol. 2014 May;71(5):543-52. doi: 10.1001/jamaneurol.2014.131. PubMed PMID: 24664227.

On 2015 Oct 07, Bill Cayley commented:

A good example of when "less-medical" is better in wound care: https://lessismoreebm.wordpress.com/?s=wound

On 2015 Mar 17, Christopher Southan commented:

This link includes the PubChem matches for the three sets of structures http://cdsouthan.blogspot.se/2015/03/getting-open-kinetoplast-data-more-open.html

On 2015 Mar 10, Donald Forsdyke commented:

ADAPTATION DECOUPLED FROM SPECIATION. This fine new paper presents an impressive synthesis of phylogenetic data aiming to “explore how it bears on evolutionary hypotheses and mechanisms of speciation and diversification.” In keeping with the results of Venditti et al. (2010) that are cited, the major conclusion is that “if adaptation is largely decoupled from speciation, we should not expect it to be a driver of speciation.” Indeed, “Cases where the phenotype has changed little (e.g. cryptic species) … are interpreted here as evidence of uncoupling.” There is reference to geographic isolation as “the major model,” but it is noted that “time constraints should be similar with ecological speciation, and other models exist.”

One of these “other models” is considered by Venditti et al. (2008 Biologist 55, 140-146), who note: “There is a growing appreciation amongst evolutionary biologists that rapid reproductive isolation is more common than previously thought and is often associated with what is known as sympatric speciation, or speciation between populations which share the same geographic range.” The idea of a non-geographic decoupling of adaptation from speciation was advanced by Darwin’s research associate George Romanes in 1886. As with Venditti et al. (2010), the present results nicely support Romanes, whose work is the major focus of my speciation text (The Origin of Species, Revisited, McGill-Queen's University Press, 2001). There is further elaboration both in our biography of the geneticist William Bateson (Treasure Your Exceptions, Springer, New York, 2008) and in my textbook Evolutionary Bioinformatics (Springer, New York, 2011).

On 2015 Jul 25, Egon Willighagen commented:

David, you may want to read with J. Wales has to say about this [0]:

But if the Professor has a more nuanced view that Wikipedia should not be cited "as a source" by university students then I agree completely! I think the same thing about citing Britannica or any other encyclopedia. Citing an encyclopedia for an academic paper at the University level is not appropriate

0.http://www.quora.com/What-does-Jimmy-Wales-think-when-a-university-professor-discourages-students-from-citing-Wikipedia-as-a-primary-or-secondary-source

On 2015 Jul 23, James M Heilman commented:

You sort of missed the point. The point is that Wikipedia is incredibly frequently read. This includes by the lay public, medical students, and physicians. One can warn people until they are blue in the face but I doubt it is going to change how frequently they use Wikipedia for medical information. In my opinion time is much better spent trying to improve the site. It really is not that difficult.

On 2015 May 11, David Gortler commented:

I have to say that although this data sounds promising, I would never use wikipedia as an authoritative resource for anything patient-related, and firmly instill warnings regarding wikipedia to my students as well. I was given a moderator account at one point and took time and effort to carefully compose several specialty pharmacology articles, only to have those articles edited incorrectly, filled with obvious biases, or inexplicably "re-organized" to the point that they were essentially vandalized. I had offenders blocked or banned, only to have scores more crawl out of the bowels of the internet to do the same. I have since stopped trying to correctly edit or even view my articles for accuracy.

The last time I used wikipedia was years ago and I think it was to look up something about vintage automobiles. I also looked up Gilligan's Island on it around the same time. That's about as far as I would trust it. Anyone who relies on wikipedia for anything clinically related is placing patient lives at risk. Anyone who relies on wikipedia to look up anything or research related is wasting their time and money.

On 2015 May 10, James M Heilman commented:

Yes looking at top editors I know most of those listed. A proportion are those who write a great deal of content and mostly work on medicine. Another proportion are those who do maintenance and vandalism reversion Wikipedia wide. What we are capturing is only a proportion of their edits as we just looked at medical editors. If we were to look at Wikipedia as a whole they would far surpass all those listed here.

So I agree on a global scale the top editors are more involved in maintenance. However within a specific area the top editors are more content contributors (there are of course still maintence people aswell).

On 2015 May 08, Gwinyai Masukume commented:

Thank you for engaging with this and making the data publicly available.

Five users appear on both lists (Top ten by number of bytes changed and Top ten by number of edits) and only one user is in the same position.

Perhaps the situation is a hybrid of Jimmy Wales’ and Aaron Swartz’s thoughts, the degree differing depending on the context. Looking forward to further insights from your data.

On 2015 May 13, James M Heilman commented:

And now we have data for 2014 https://en.wikipedia.org/wiki/Wikipedia:WikiProject_Medicine/Stats/Top_English_medical_editors_2014

On 2015 May 07, James M Heilman commented:

We now have data looking at the top editors for 2013 based on bytes changed here https://en.wikipedia.org/wiki/Wikipedia:WikiProject_Medicine/Stats/Top_English_medical_editors_2013b

There is a fairly good relationship with top editors for 2013 based on number of edits here https://en.wikipedia.org/wiki/Wikipedia:WikiProject_Medicine/Stats/Top_English_medical_editors_2013

So my analysis is more in line with the thoughts of Jimmy Wales rather than Aaron Swartz.

On 2015 Mar 26, James M Heilman commented:

Often people with the highest edit count also have the largest number of bytes changed.

One would really want to look at the persistent bytes contributed by a user. One also needs to keep in mind that more text is not necessarily better text. Lots of improvements involved trimming material.

Agree that their is no perfect measure of "authorship" which can be carried out in an automated fashion. Will look at running the analysis you suggest and posting the results here.

On 2015 Mar 21, Gwinyai Masukume commented:

The authors use the number of edits made to measure participation. An edit, for example, can be adding a full stop/period “.” or it can be adding a whole paragraph. Each of these actions would be counted as one edit.

Another way to measure participation is by considering the amount of text added by a contributor. This approach of considering the amount of text added has in the past yielded different results and insights compared to considering the number of edits made. Some contributors with relatively low edit counts have been found to have added a relatively high amount of text.

I am of the view that only using edit counts is a limitation. This limitation could have been remedied by considering the amount of text added by contributors from a limited number of randomly selected articles from the authors' sampling frame.

Reference

Swartz A. Who writes Wikipedia? 2006. Available: http://www.aaronsw.com/weblog/whowriteswikipedia (accessed 21 March 2015).

On 2016 Aug 23, Ben Goldacre commented:

This trial has the wrong trial registry ID associated with it on PubMed: both in the XML on PubMed, and in the originating journal article. The ID given is NCT0157384. We believe the correct ID, which we have found by hand searching, is NCT01573845.

This comment is being posted as part of the OpenTrials.net project^[1] , an open database threading together all publicly accessible documents and data on each trial, globally. In the course of creating the database, and matching documents and data sources about trials from different locations, we have identified various anomalies in datasets such as PubMed, and in published papers. Alongside documenting the prevalence of problems, we are also attempting to correct these errors and anomalies wherever possible, by feeding back to the originators. We have corrected this data in the OpenTrials.net database; we hope that this trial’s text and metadata can also be corrected at source, in PubMed and in the accompanying paper.

Many thanks,

Jessica Fleminger, Ben Goldacre*

[1] Goldacre, B., Gray, J., 2016. OpenTrials: towards a collaborative open database of all available information on all clinical trials. Trials 17. doi:10.1186/s13063-016-1290-8 PMID: 27056367

* Dr Ben Goldacre BA MA MSc MBBS MRCPsych<br> Senior Clinical Research Fellow<br> ben.goldacre@phc.ox.ac.uk<br> www.ebmDataLab.net<br> Centre for Evidence Based Medicine<br> Department of Primary Care Health Sciences<br> University of Oxford<br> Radcliffe Observatory Quarter<br> Woodstock Road<br> Oxford OX2 6GG

On 2017 Jul 13, Randi Pechacek commented:

Bubba Brooks, co-author of this paper, wrote a blog on microBEnet giving background and commentary.

On 2015 Apr 21, David Keller commented:

Clinical recommendations should not be biased by economic considerations

These recommendations for treatment of pressure ulcers ("bed sores") ignore the evidence in favor of certain mattress types, simply because of cost considerations. For example, air-fluidized beds have moderate quality evidence of reducing pressure ulcer size, compared with other surfaces, leading to an improved overall treatment effect (see Table 3 of this paper). In trying to understand why air-fluidized beds were not included in the recommended treatments for pressure ulcers, I noted that the section on "High Value Care" states that "the use of advanced support surfaces adds unnecessary costs to the health care systems". However, the evidence demonstrating improvement due to electrical stimulation was of similar quality ("moderate") as air-fluidized beds. Electrical stimulation was included in the recommended treatments for pressure ulcers. Is electrical stimulation really less expensive than an air-fluidized bed, after accounting for the professional fees charged by the clinician providing that service? How many communities have such a clinician? The cost of air-fluidized beds, like any other commodity, is flexible and based on the volume of orders received. A recommendation by ACP for air-fluidized beds would increase the number of orders and decrease the cost of such beds, due to economies of scale. Economic considerations should not bias clinical recommendations. We are physicians, not economists. We should make recommendations purely on the basis of clinical benefits, and leave the economic analysis to experts in that field, who are more qualified to provide such analysis.

On 2015 Sep 18, Sacha Laurent commented:

I've written an opinion piece on my blog where I discuss the findings of this paper and their impact on the "evolutionary success polyploids" debate. I'll be happy to get any feedback or opinion. Yours,

On 2016 Jan 01, Jaime A. Teixeira da Silva commented:

I have self-published my views on this paper.

Teixeira da Silva, J.A. (2016) Assessing the potentially misleading nature of metrics and of those who assess and create them. Self-published 4 pp. https://www.researchgate.net/publication/288835044

On 2016 Jan 11, BSH Cancer Screening, Help-Seeking and Prevention Journal Club commented:

Relevant to our current research goals, the HBRC journal club was interested to review this paper with particular interest in adding to our understanding of the role of descriptive norms in cancer risk-reducing behaviours. The paper demonstrates a strong rationale for investigating the role of descriptive norms in established risk-reducing behaviours, and in uncertain and relatively unknown behaviours. Furthermore, it offers an additional explanation to the reasons why descriptive norm literature is usually inconsistent, or every so often insignificant for health-behaviour change.

The study employed a cross-sectional design that included an opportunistic sample aged 18 to 95, and reported the use of a theoretical framework, known as the Integrative Model of Behavioural Prediction, which strengthened the methodology of the paper. Although the authors acknowledged their decision for defining uncertainty as a limitation, they attributed the uncertainty of risk-reducing behaviours using scientific knowledge rather than public perceptions of the uncertainty of the behaviours. However, we felt that the study might have benefited from the inclusion of other elements such as beliefs about causes of cancer, scientific literacy, or specifically knowledge, and controlling for age to evaluate further associations with descriptive norms and scientific uncertainty.

The journal club also discussed the possibility of controlling for individuals’ current health behaviours as another factor that could influence descriptive norms. We also deliberated on whether the established risk-reducing behaviours are also linked to other chronic illnesses, therefore; there may be differences in motivations to take up those behaviours.

Overall, the HBRC journal club enjoyed reading this article and feel that the paper is an important example of using integrated theoretical models which could improve the way we implement theoretically grounded research.

Conflicts of interest. We report no conflict of interests and note that the comments produced by the group are collective and not the opinion of any one individual.

On 2015 Mar 03, Robert Eibl commented:

Looks like a great, new approach; fascinating.

On 2015 Mar 27, James M Heilman commented:

A great analysis of this paper exists here https://en.wikipedia.org/wiki/Wikipedia:Wikipedia_Signpost/2015-03-25/Recent_research

"A paper in Advances in Physiology Education[2] claims to assess the suitability of Wikipedia's respiratory articles for medical student learning. Forty Wikipedia articles on respiratory topics were sampled on 27 April 2014. These articles were assessed by three researchers with a modified version of the DISCERN tool. Article references were checked for accuracy and typography. Readability was assessed with the Flesch–Kincaid and Coleman–Liau tools.

The paper found a wide range of accuracy scores using the modified DISCERN tool, from 14.67 for "[Nail] clubbing" to 38.33 for "Tuberculosis". Incorrect, incomplete or inconsistent formatting of references were commonly found, although these were not quantified in the paper. Readability of the articles was typically at a college level. On the basis of these findings, the paper declares Wikipedia's respiratory articles as unsuitable for medical students.

The researcher apparently uses an arbitrary unvalidated modification of the DISCERN tool to assess the accuracy of articles. The nature of this modification is not specified; nor is it available at the journal's website as claimed in the paper.

The DISCERN tool does not assess accuracy; rather, it is designed to assess "information about treatment choices specifically for health consumers". As such, the use of this tool is inappropriate to assess the suitability for medical students.

There is no acknowledgement that Wikipedia is an encyclopedia. Several of the DISCERN tool's questions are unsuitable for an encyclopedia. DISCERN questions such as "Does it describe how each treatment works?" and "Does it describe the risks of each treatment?" would be answered on other Wikipedia pages, not on the disease article's page. The author makes an a priori assumption that the medical textbooks used for comparison are perfect sources. The author does not assess those textbooks with the DISCERN tool.

The paper states: "[t]he number of citations from peer-reviewed journals published in the last 5 yr was only 312 (19%)." However this is far superior to the number of citations in the textbooks listed. The chapter on "Neoplasms of the lung" in Harrison's Principles of Internal Medicine (18th ed.) contains no citations at all. Seven sources are listed in its "Further readings" section, of which only one is from the last five years.

The claim that the article on "clubbing ... had no references or external links" is incorrect. On 27 April 2014, Wikipedia's article on "Nail clubbing" had ten references.

Several of the articles are at a rudimentary stage, containing limited information and lacking appropriate references. However two articles, "Lung cancer" and "Diffuse panbronchiolitis", were assessed by Wikipedia's editors at the highest standard and awarded "Featured article" status. Five more articles, "Asthma", "Chronic obstructive pulmonary disease", "Pneumonia", "Pneumothorax" and "Tuberculosis", reached "Good article" standard. These articles are exceptionally detailed, accurate, and well-referenced. Azer's paper makes no mention of the high quality of these articles.

The research uses an unvalidated tool for an inappropriate purpose without applying a suitable comparator, and inevitably draws incorrect conclusions.

Wikipedia is an encyclopedia. It is not a medical textbook; nor is it intended to replace medical textbooks. Rather, it should be used as a starting point by medical students. The quality of an individual article should be quickly assessed by the reader, and information can be confirmed in the references provided. Missing information should be sought from other sources, such as textbooks. Students should be encouraged to use Wikipedia alongside medical textbooks to assist their learning."

It is by User:Axl and is under a CC BY SA license

On 2016 Jul 05, STEPHEN ROPER commented:

Despite the impressive technique and the many fine figures in this paper, the findings regarding the microvascular permeability in taste buds (Fig 4) are deeply flawed. Specifically, the authors purport to show that compounds such as fluorescein injected into the blood stream have ready access to the cells within taste buds (Fig. 4g-i). Regrettably, this figure, and specifically Fig 4h, reveals a serious misconception about taste buds. This micrograph shows fluorescein-laden lingual surface epithelial squames surrounding the taste bud pore. It does NOT show taste cells. The taste bud itself lies below this plane of focus. Because the quantification in Fig 4i is taken from Fig 4h, it thus is correspondingly in error. Compounds injected into the bloodstream indeed have ready access to the stratified lingual epithelium, including superficial layers, as shown by a previous publication (Dando et al, 2015, Am J Physiol Cell Physiol. 308:C21-32. Epub 2014 Sep 10).

In fact, contrary to the conclusions reported here, there is some form of selectively permeable barrier protecting taste bud cells from many blood-borne chemicals (ibid.). Indeed, Fig. 4g of Choi et al may be consistent with such a barrier, assuming that the relatively fluorescein-free central area in this micrograph is a taste bud. [It might merely be the somewhat acellular connective tissue core of the papilla. This would also be relatively free of fluorescein].

On 2015 Mar 18, George McNamara commented:

See also

Assessing the prevalence of mycoplasma contamination in cell culture via a survey of NCBI's RNA-seq archive. Olarerin-George AO, Hogenesch JB. Nucleic Acids Res. 2015; 43(5): 2535-42. doi: 10.1093/nar/gkv136. PMID: 25712092 Mycoplasmas are notorious contaminants of cell culture and can have profound effects on host cell biology by depriving cells of nutrients and inducing global changes in gene expression. Over the last two decades, sentinel testing has revealed wide-ranging contamination rates in mammalian culture. To obtain an unbiased assessment from hundreds of labs, we analyzed sequence data from 9395 rodent and primate samples from 884 series in the NCBI Sequence Read Archive. We found 11% of these series were contaminated (defined as ≥100 reads/million mapping to mycoplasma in one or more samples). Ninety percent of mycoplasma-mapped reads aligned to ribosomal RNA. This was unexpected given 37% of contaminated series used poly(A)-selection for mRNA enrichment. Lastly, we examined the relationship between mycoplasma contamination and host gene expression in a single cell RNA-seq dataset and found 61 host genes (P < 0.001) were significantly associated with mycoplasma-mapped read counts. In all, this study suggests mycoplasma contamination is still prevalent today and poses substantial risk to research quality.

On 2015 Sep 01, Coby Viner commented:

A version of this article is now publicly available from TSpace (University of Toronto's institutional repository). The post-print version remains available from the publisher.

On 2016 Jan 16, Lewis G Halsey commented:

Fay worries that in the real world of data collection, the power of a study is not known in advance. If true, this argument would only compound our own, which is that unless power is very high (>90%) P has surprisingly low repeatability (Halsey et al., 2015), and the power of most studies calculated after the data analysis is far lower than this (Button et al., 2013, Maxwell, 2004). Therefore, researchers would not be able to design their experiment to ensure it has a very high power, and they could not rely on good fortune instead for their experiment to turn out this way.

But anyway, an integral step in testing the null hypothesis generates an estimate of the variance of the pooled population. Using this estimated parameter, obtained as the data are analysed, the researcher can immediately gauge the study’s power. The exact parameters of the population are never known. These parameters are hypothesised and then estimated, with varying certainty, according to the sample that we have. With a limited sample, these estimates can vary substantially each time an experiment is repeated. If our samples, and the estimates they generate, suggest that power is poor, then any P value that we obtain, low or not, is untrustworthy. A small P value is of little import: a repetition of the same study would give another result (our study, figure 4). This is like looking at the world through a pinhole. When the theoretical power is 0.48, P values less than 0.05 are no more likely than P values greater than 0.05. Why get excited if P is <0.01, when the next replicate experiment could give a P of 0.6?

Fay asks if there is a single better measure than P to test the likelihood that the null hypothesis is untenable. First, this brings us back to the nub of the problem - P is only a good test of the null in the ideal circumstances that study power is very high. Second, there are long-held, big concerns about the value of null hypothesis significance testing as a method for analysing and interpreting data (Cohen, 1994).

Lewis G Halsey and Gordon B Drummond

BUTTON, K., IOANNIDIS, J., MOKRYSZ, C., NOSEK, B., FLINT, J., ROBINSON, E. & MUNAFO, M. (2013) Power failure: why small sample size undermines the reliability of neuroscience. Nature Reviews Neuroscience, 14, 365-376. COHEN, J. (1994) The Earth is round (p < 0.05). American Psychologist 49, 997-1003. HALSEY, L., CURRAN-EVERETT, D., VOWLER, S. & DRUMMOND, G. (2015) The fickle P value generates irreproducible results. Nature Methods, 12, 179-185. MAXWELL, S. (2004) The persistence of underpowered studies in psychological research: Causes, consequences, and remedies. Psychological Methods, 9, 147-163.

On 2016 Jan 13, Mike Fay commented:

Halsey, Curran-Everett, Vowler, and Drummond (2015) correctly point out that P values are variable and that estimates and confidence intervals often provide more useful information. I disagree with some of the apparent implications they make from these points. For example, they state “The P value is often used without the realization that in most cases the statistical power of a study is too low for P to assist the interpretation of the data.” The problem with this statement is that in practice we never know the statistical power of a study, so we never know if it is too low. The statistical power is a function of the sample size, the statistical model and the true value of the parameters. If the statistical model describes the data generating process and we knew the true value of the parameters, then we could know the power. The problem is that we collect data precisely because we do not know the true value of the parameters, and hence do not know the power. So we never know if the power of a study is “too low”. P can assist in interpreting the data. The P value represents the probability of observing equal or more extreme data when the null hypothesis is true. So small values of the P value imply that the null hypothesis is not likely to hold.

Here is another quote from the paper: “Put simply, the P value is usually a poor test of the null hypothesis.” This statement begs the question, is there another single statistic that is better to test the null hypothesis? If you want one statistic to test the null hypothesis, the P value is just the statistic to do that. So the P value is not “flawed” (see last paragraph of the article), but is one statistic designed to perform one function. Certainly, P values should not be the whole statistical story for any data set, but they can work for what they are designed to do.

On 2015 Mar 02, William Grant commented:

For a paper on how increasing vitamin D intake and levels might reduce the mortality rates for those with disabilities, see this open access paper: Grant WB, Wimalawansa SJ, Holick MF, Cannell JJ, Pludowski P, Lappe JM, Pittaway M, May P. Emphasizing the health benefits of vitamin D for those with neurodevelopmental disorders and intellectual disabilities. Nutrients. 2015, 7, 1538-1564. http://www.mdpi.com/2072-6643/7/3/1538

On 2016 Feb 05, Christopher Southan commented:

zileuton = http://www.guidetopharmacology.org/GRAC/LigandDisplayForward?ligandId=5297 (but racemate)

MMV007384 = https://pubchem.ncbi.nlm.nih.gov/compound/17325420

MMV666023 = https://pubchem.ncbi.nlm.nih.gov/compound/2853195

MMV665805 = https://pubchem.ncbi.nlm.nih.gov/compound/16437129

On 2015 Aug 19, Bill Cayley commented:

A good example of when less-medical is better: https://lessismoreebm.wordpress.com/2015/07/02/allergy-in-children-in-hand-versus-machine-dishwashing/

On 2015 Mar 05, Ivan Oransky commented:

Mario Saad, one of the authors of the four papers subject to this expression of concern, has sued the journal to force them to remove the expression of concern, and to prevent them from retracting the papers: http://retractionwatch.com/2015/03/05/researcher-asks-court-to-overturn-motion-denying-his-request-to-quash-expressions-of-concern/

On 2016 Jan 08, Andrea Messori commented:

Drug-drug interactions in oncology

A.Messori, HTA Unit, Regional Health Service, 50100 Firenze, Italy and SIFACT (Società Italiana di Farmacia Clinica e Terapia), 20100 Milano

In the field of oncology, drug-drug interactions (DDIs) represent a topic in which a large amount of information is available. Hence, a critical selection in this area is generally thought to be needed to maximize the usefulness of recommendations and to avoid an overload of messages. In this selection process, two criteria are most frequently advocated: (1): prioritizing the DDIs showing a marked clinical relevance (that, in the main data banks, are denoted as major interactions or contra-indications); (2): prioritizing those DDIs the frequency of which is not negligible and has been documented in the real-world setting. The first point is adequately addressed by the scores assigned to single DDIs in the most authoritative data banks (e.g. Micromedex). As regards the second point, the reference list reported below indicates which DDIs have been most frequently found in the main studies conducted on this topic in cancer patients. References 1. Carcelero E, Anglada H, Tuset M, Creus N. Interactions between oral antineoplastic agents and concomitant medication: a systematic review. Expert Opin Drug Saf. 2013 May;12(3):403-20. doi: 10.1517/14740338.2013.784268. Epub 2013 Apr 16. Review. PubMed PMID: 23586848.

1. Chan A, Tan SH, Wong CM, Yap KY, Ko Y. Clinically significant drug-drug interactions between oral anticancer agents and nonanticancer agents: a Delphi-survey of oncology pharmacists. Clin Ther. 2009;31 Pt 2:2379-86. doi: 10.1016/j.clinthera.2009.11.008. PubMed PMID: 20110047.

2. Depont F, Vargas F, Dutronc H, Giauque E, Ragnaud JM, Galpérine T, Abouelfath A, Valentino R, Dupon M, Hébert G, Moore N. Drug-drug interactions with systemic antifungals in clinical practice. Pharmacoepidemiol Drug Saf. 2007 Nov;16(11):1227-33. PubMed PMID: 17879355.

3. Girre V, Arkoub H, Puts MT, Vantelon C, Blanchard F, Droz JP, Mignot L. Potential drug interactions in elderly cancer patients. Crit Rev Oncol Hematol.2011 Jun;78(3):220-6. doi: 10.1016/j.critrevonc.2010.05.004. Epub 2010 Jul 1. Review. PubMed PMID: 20594867.

4. Kotlinska-Lemieszek A, Klepstad P, Haugen DF. Clinically significant drug-drug interactions involving opioid analgesics used for pain treatment in patients with cancer: a systematic review. Drug Des Devel Ther. 2015 Sep 16;9:5255-67. doi: 10.2147/DDDT.S86983. eCollection 2015. Review. PubMed PMID: 26396499; PubMed Central PMCID: PMC4577251.

5. Kruse V, Somers A, Van Bortel L, De Both A, Van Belle S, Rottey S. Sunitinib for metastatic renal cell cancer patients: observational study highlighting the risk of important drug-drug interactions. J Clin Pharm Ther. 2014 Jun;39(3):259-65. doi: 10.1111/jcpt.12134. Epub 2014 Jan 13. PubMed PMID:24417304.

6. Miranda V, Fede A, Nobuo M, Ayres V, Giglio A, Miranda M, Riechelmann RP. Adverse drug reactions and drug interactions as causes of hospital admission in oncology. J Pain Symptom Manage. 2011 Sep;42(3):342-53. doi: 10.1016/j.jpainsymman.2010.11.014. Epub 2011 Mar 31. PubMed PMID: 21454043.

7. Riechelmann RP, Del Giglio A. Drug interactions in oncology: how common are they? Ann Oncol. 2009 Dec;20(12):1907-12. doi: 10.1093/annonc/mdp369. Epub 2009 Aug 27. Review. PubMed PMID: 19713244.

8. Stoll P, Kopittke L. Potential drug-drug interactions in hospitalized patients undergoing systemic chemotherapy: a prospective cohort study. Int J Clin Pharm. 2015 Jun;37(3):475-84. doi: 10.1007/s11096-015-0083-6. Epub 2015 Feb 25. PubMed PMID: 25711852.

9. Teo YL, Ho HK, Chan A. Metabolism-related pharmacokinetic drug-drug interactions with tyrosine kinase inhibitors: current understanding, challenges and recommendations. Br J Clin Pharmacol. 2015 Feb;79(2):241-53. doi:10.1111/bcp.12496. Review. PubMed PMID: 25125025; PubMed Central PMCID: PMC4309630.

10. Turner JP, Shakib S, Singhal N, Hogan-Doran J, Prowse R, Johns S, Bell JS. Prevalence and factors associated with polypharmacy in older people with cancer. Support Care Cancer. 2014 Jul;22(7):1727-34. doi: 10.1007/s00520-014-2171-x. Epub 2014 Mar 2. Erratum in: Support Care Cancer. 2014 Jul;22(7):1735. PubMed PMID:24584682.

11. van Leeuwen RW, Brundel DH, Neef C, van Gelder T, Mathijssen RH, Burger DM, Jansman FG. Prevalence of potential drug-drug interactions in cancer patients treated with oral anticancer drugs. Br J Cancer. 2013 Mar 19;108(5):1071-8. doi: 10.1038/bjc.2013.48. Epub 2013 Feb 14. PubMed PMID: 23412102; PubMed CentralPMCID: PMC3619066.

12. van Leeuwen RW, van Gelder T, Mathijssen RH, Jansman FG. Drug-druG interactions with tyrosine-kinase inhibitors: a clinical perspective. Lancet Oncol. 2014 Jul;15(8):e315-26. doi: 10.1016/S1470-2045(13)70579-5. Review. PubMed PMID: 24988935.

13. Voll ML, Yap KD, Terpstra WE, Crul M. Potential drug-drug interactions between anti-cancer agents and community pharmacy dispensed drugs. Pharm World Sci. 2010 Oct;32(5):575-80. doi: 10.1007/s11096-010-9410-0. Epub 2010 Jul 20.PubMed PMID: 20645002.

On 2015 Mar 30, John Cannell commented:

In Denmark, like all Scandinavian countries, the use of cod liver oil is common. Cod liver oil will raise 25(OH)D levels but also increase vitamin A intake. Increased vitamin A intake has been associated with increased mortality. This would explain the J shaped relationship found by the authors.

Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C. supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database Syst Rev. 2008 Apr 16;(2):CD007176.

On 2015 Feb 25, Sundeep Salvi commented:

The sexual dysfunction seen only in Type I diabetic females could be due to use of Insulin rather than other causes as mentioned. Among Type 2 diabetic females, how many were receiving insulin? Was there a difference in sexual dysfunction between Type 2 diabetic females using insulin and those not using insulin?

On 2017 May 19, Zvi Herzig commented:

The methodology of this study would lead to unrealistic overheating producing unrealistically high levels of toxicants. The authors note:

The E-cigarette puffs were actuated by a pump and programmed to cycle every 15 seconds until the cartridge was empty. Each actuation was 6 seconds...

However, puffing an e-cigarette until the cartridge is empty would lead to overheating when liquid levels fall low, which users avoid, but entails high levels of toxicant production Farsalinos KE, 2013 Farsalinos KE, 2015.

Also, users have been shown to take four-second puffs with 20-30 s intervals Farsalinos KE, 2013. Increasing puff duration and decreasing the time of the cycle between puffs would also increase overheating.

On 2017 Sep 09, Louise B Andrew MD JD commented:

Reason(s) for withdrawal?

On 2015 Apr 21, David Keller commented:

The observed association between sauna bathing and improved cardiovascular outcomes may be due to self-selection bias

Persons at higher risk for adverse cardiac events may experience unpleasant symptoms due to the tachycardia induced by sitting in a hot sauna, such as mild dyspnea, orthostasis, or chest discomfort, at higher frequency or severity than persons in good cardiovascular health, These adverse symptoms might cause them to avoid saunas, thereby biasing the group of sauna-takers to include persons at lower risk of adverse cardiac events than the general public.

The authors suggest that, based on this study, "sauna bathing is a recommendable health habit". I disagree, and suggest that physicians should await the results of a randomized trial of sauna bathing before we recommend it for health enhancement. Only randomized trials can provide the quality of evidence required for a physician to recommend a potentially dangerous intervention for health enhancement. Observational studies such as this one are supposed to be for "hypothesis generation" only.

On 2015 Mar 04, Raphael Stricker commented:

In this one-sided opinion piece about Lyme disease, Eugene Shapiro once again finds "no evidence that viable B. burgdorferi persist in humans after conventional treatment with antimicrobials". Shapiro is a well known member of the shrinking "Lyme Denialist" cabal that views Lyme disease as a trivial illness that is "hard to catch and easy to cure", apparently ignoring the latest CDC figures showing more than 300,000 new cases per year in the USA. The fact that Lyme disease has become a major epidemic that is six times more common than HIV/AIDS in this country fails to impress Shapiro, who adheres to the dogma that persistent infection with B. burgdorferi, the Lyme spirochete, does not exist following short-course antibiotic therapy despite extensive evidence to the contrary (Stricker & Johnson, Infect Drug Resist 4: 1-9, 2011; Cameron et al, Expert Rev. Anti Infect. Ther. 12:1103-1135, 2014).

Significant controversy over Lyme disease exists for three main reasons: (1) lack of accurate and/or universally accepted testing for the disease, (2) disagreement about symptoms associated with persistent infection in chronic Lyme disease, and (3) misinterpretation and misrepresentation of underpowered Lyme antibiotic treatment trials. While many studies describe the constellation of musculoskeletal, neurocognitive and/or cardiac symptoms associated with chronic Lyme disease, Shapiro views these as "medically unexplained symptoms" not necessarily related to persistent B. burgdorferi infection. Without a universally accepted "gold standard" test, the controversy over persistent infection and optimal therapy continues to smoulder while thousands of patients continue to suffer due to the dogma espoused by Shapiro (Johnson et al. PeerJ 2:e322, 2014).

A major problem faced by Shapiro is that he is trying to prove a negative. Thus if there is any evidence that persistent infection with B. burgdorferi does exist following short-course antibiotic therapy, his opinion is obviously wrong. To address this problem, Shapiro narrows his evidence to two recent Lyme disease articles, ignoring numerous studies in animals and humans that support persistent infection or leave the issue unsettled (Cairns & Godwin, Int J Epidemiol 34: 1340-1345, 2005; Berndtson, Int J Gen Med 6: 291-306, 2013; Stricker & Johnson, PLoS Pathog 10: e1003796, 2014). Shapiro dismisses this contrary evidence as "speculative", but his narrow selection of two "convincing" studies is insufficient to support his biased conclusion.

The first study examined a group of 17 patients with recurrent erythema migrans (EM) rashes who were promptly treated for their initial episode of Lyme disease and then developed one or more EM rashes at a later date. Culture of the rashes revealed different strains of B. burgdorferi in the subsequent episodes, and Shapiro points to this as evidence for new infection rather than relapse in these patients. However as pointed out in a letter addressing the article, this is a poor model for chronic Lyme disease due to persistent infection because all patients were promptly treated for their initial illness, lived in endemic areas and most likely were reinfected with a different strain of the spirochete from a subsequent tickbite. This is a very different situation from a patient who may have been infected and never treated for months to years and develops the constellation of musculoskeletal, neurocognitive and/or cardiac symptoms that are characteristic of persistent infection with the Lyme spirochete (Donta, N Engl J Med 368:1063-1064, 2013). Thus the model for persistent infection in this study is flawed.

The second study was a xenodiagnosis safety study of 36 patients (26 Lyme patients in different stages of disease and 10 controls) who allowed ticks to feed on them, and the ticks were then examined for B. burgdorferi transmission. Shapiro states that "no viable B. burgdorferi were cultured from ticks fed on any of these patients". This conclusion is flawed for two reasons: First, 30-50% of ticks were lost during the study, rendering the transmission results uninterpretable. Second, one patient with post-treatment Lyme disease syndrome (PTLDS) was found to have a positive culture from one tick, as stated in the Results: "One nymph was found to be positive by PCR of the nymph lysate culture, but direct PCR of the nymph lysate and microscopic evaluation of the culture were negative....The original positive OspA PCR of the tick culture was confirmed by PCRs for other B. burgdorferi genes.... The DNA extracted from this culture sample was then tested by IA/PCR/ESI-MS, which was positive for 7 of the 8 assay primer pairs" (emphasis added). Thus this patient had culture-confirmed evidence of persistent infection with the Lyme spirochete in PTLDS. Shapiro generously states that this finding is "provocative" when in fact it provides definitive evidence that he is wrong.

In summary, this one-sided opinion piece will only add to the confusion and misinformation surrounding Lyme disease. With better testing and novel treatments, a solution to this tickborne disease will someday be found. Shapiro's muddled article fails to contribute to this solution.

Disclosure: RBS is a member of the International Lyme and Associated Diseases Society (ILADS) and a director of LymeDisease.org. He has no financial or other conflicts to declare.

On 2016 Sep 23, Israel Hanukoglu commented:

The link to the Proteopedia page with animations and examples: http://www.proteopedia.org/w/Rossmann_fold

On 2017 Jul 10, Randi Pechacek commented:

Rachel Adams, first author of this paper, wrote a blog post on microBEnet to provide some background.

On 2016 Mar 08, Kenneth Witwer commented:

Because of continuing interest in this topic, an extended version of these comments has been deposited on the "Negative Results" track on ResearchGate.

On 2015 Mar 04, Avinash Bidra commented:

My response to these comments can be found at: http://www.ncbi.nlm.nih.gov/pubmed/25702969

On 2016 Mar 18, ZHONGMING ZHAO commented:

My lab recently moved to the University of Texas Health Science Center at Houston. The software is now available at https://bioinfo.uth.edu/VirusFinder/.

On 2015 Mar 19, Donna Beales commented:

My understanding is that there was a change to the formulation of the suspension medium used in some trials with T. suis ova. Such alterations could conceivably have unanticipated effects on living organism therapies. Quoted as follows: All prior and very successful studies, this final formulation was of a pH value between 2.7 – 3 and had no preservative, while for the TRUST and some other newly pilot studies on other indications a formulation of a pH value of 5 plus potassium sorbate as a preservative was used... Nevertheless, the decision of changing the formulation for the drug approval studies is understandable if one takes into account what the common practice is in normal drug development according to the pharmacopeia, but a living organism does not necessarily fit into these regulations designed for single molecules and chemical compounds."

Too, 12 weeks may not be sufficient time for clinical efficacy with a living organism; even pharmaceutical immunosuppressants may require a period of several months for full effectiveness. "Another critical issue in the TRUST studies was that the endpoint was set after just 12 weeks of treatment, which is known to be the time frame where the agent just begins to unfold its mode of action effectively." Source: http://tanawisa.com/news/

These factors are relatively unknown, and should be considered in any interpretation of study conclusion.

On 2015 Apr 22, Hans-Peter Müller commented:

Response to Müller HP. Direct and CBCT dentogingival tissue thickness measurements. Oral Surg Oral Med Oral Pathol Oral Radiol 2015; 119: 482-481. http://www.ncbi.nlm.nih.gov/pubmed/25687197

On 2016 Aug 30, Ben Goldacre commented:

This trial has the wrong trial registry ID associated with it on PubMed. The ID given is NCT014182482377 - the correct ID, which we found within the text of the article itself, is NCT00962377.

This comment is being posted as part of the OpenTrials.net project^[1] , an open database threading together all publicly accessible documents and data on each trial, globally. In the course of creating the database, and matching documents and data sources about trials from different locations, we have identified various anomalies in datasets such as PubMed, and in published papers. Alongside documenting the prevalence of problems, we are also attempting to correct these errors and anomalies wherever possible, by feeding back to the originators. We have corrected this data in the OpenTrials.net database; we hope that this trial’s text and metadata can also be corrected in PubMed.

Many thanks,

Jessica Fleminger, Ben Goldacre*

[1] Goldacre, B., Gray, J., 2016. OpenTrials: towards a collaborative open database of all available information on all clinical trials. Trials 17. doi:10.1186/s13063-016-1290-8 PMID: 27056367

* Dr Ben Goldacre BA MA MSc MBBS MRCPsych<br> Senior Clinical Research Fellow<br> ben.goldacre@phc.ox.ac.uk<br> www.ebmDataLab.net<br> Centre for Evidence Based Medicine<br> Department of Primary Care Health Sciences<br> University of Oxford<br> Radcliffe Observatory Quarter<br> Woodstock Road<br> Oxford OX2 6GG

On 2015 Feb 23, William Grant commented:

Concerns over Vitamin D and clinical practice at a crossroads recommendations

In their viewpoint piece, Vitamin D and clinical practice at a crossroads, Manson and Bassuk state among other things that the Institute of Medicine (IOM) set the recommended dietary allowance for vitamin D at 600 IU/d for those living in the upper latitudes of North America aged to 70 years and 800 IU/d for those older in order to reach a 25-hydroxyvitamin D [25(OH)D] concentration of 20 ng/mL (50 nmol/L) [1]. However, it is not clear how the Dietary Reference Intakes for Calcium and Vitamin D committee arrived at that number. For example, on p. 3-20 of the vitamin D and calcium IOM report [2], Figure 3-4 from Cashman et al. [3] is given as Figure 3-4, although without the 95% confidence intervals as in the original paper. The results were based on a 22-week placebo, randomized controlled supplementation study involving men and women aged 20-40 years. Inspection of Figure 2 in Ref. 3 indicates that it would take 1155 IU/d vitamin D3 for 97.5% of the 20-40 year old population sampled to reach 50 nmol/L. In a subsequent paper based on a systematic review and meta-analysis of vitamin D intake and 25(OH)D concentrations, the same group determined that it would take 930 IU/d vitamin D3 for people living in northern Europe to reach 50 nmol/L [4]. Further complicating matters is the fact that not all of the contributions from diet are accounted for in most studies. It is becoming apparent that some food such as meat has vitamin D in the form of 25(OH)D. Thus, vegans in the UK have 25(OH)D concentrations 20 nmol/L lower than omnivores [5], so require higher vitamin D intake from non-dietary sources or solar UVB exposure.

Their comment that "while awaiting the results of the large trials now in progress, physicians would be well advised to follow current USPSTF and IOM recommendations and avoid overscreening and overprescribing supplemental vitamin D" is also not well grounded. The IOM restricted its assessment of the benefits of vitamin D to vitamin D randomized controlled trials [RCTs] with substantial benefits by 2010. A number of trials since then demonstrated health benefits, e.g., for biomarkers of inflammation, where it was found that RCTs with baseline 25(OH)D concentrations below 48 nmol/L had a 50% chance of findings benefits from vitamin D supplementation compared to 25% with baseline 25(OH)D concentrations above 50 nmol/L [6]. In addition, ecological, observational, clinical, and laboratory studies have found many health benefits of solar UVB exposure and/or vitamin D. Since the IOM report was published (29 November, 2010), 13,535 publications with vitamin D in the title or abstract have been published at PubMed.gov as of 23 February, 2015, compared with 27,775 published before that date. Many of these publications strengthen the case for vitamin D supplementation and UVB exposure.

In terms of confounding factors related to observational studies, one not mentioned in Ref. 1 is the possibility that solar UV exposure may have health benefits in addition to vitamin D production. As a result, 25(OH)D concentrations may be an index of UVB exposure. Beneficial effects of UV exposure in addition to vitamin D production have been reported for intestinal cancer [7], multiple sclerosis [8], and blood pressure [9].

As for concern about adverse effects of higher 25(OH)D concentrations based on observational studies, it should be noted that most such studies do not obtain any information from participants about vitamin D supplementation prior to having 25(OH)D concentrations measured. Thus, those with adverse health outcomes and high 25(OH)D concentrations may have started taking vitamin D supplements shortly before blood draw. For example, studies of frailty vs. 25(OH)D concentration found a U-shaded relation for elderly women [10] but a linear inverse relation for elderly men [11]. Elderly women in the U.S. are much more likely to be advised to take vitamin D supplements than men, and starting to take vitamin D late in life cannot erase the adverse effects of years of low 25(OH)D concentrations. In addition, meta-analyses of observational studies of health outcomes with respect to 25(OH)D concentrations do not show U-shaped relations for cardiovascular disease [12] or all-cause mortality rates [13].

As to their comment regarding how interest in vitamin D could jeopardize ongoing vitamin D RCTs, that should not be the case if trial participants are screened by measuring 25(OH)D concentration prior to acceptance and including only those with 25(OH)D concentrations below 50 nmol/L then dropping any who are subsequently prescribed supplements in excess of the IOM recommendations. Over 99% of the population is not enrolled in vitamin D RCTs and should not be held hostage to ongoing or planned trials since there appear to be many health benefits and very few risks of vitamin D supplementation below 4000 IU/d [14] even by the IOM's admission [2].

References 1. Manson JE, Bassuk SS. Vitamin D research and clinical practice: at a crossroads. JAMA. 2015 Feb 19. doi: 10.1001/jama.2015.1353. [Epub ahead of print] 2. Ross AC, Taylor CL, Yaktine AL, Del Valle HB, eds. ; Committee to Review Dietary Reference Intakes for Vitamin D and Calcium; Dietary Reference Intakes for Calcium and Vitamin D. Institute of Medicine. ISBN: 0-309-16395-1, 482 pages, (2010) Available from National Academies Press at: http://www.nap.edu/catalog/13050.html 3. Cashman KD, Hill TR, Lucey AJ, et al. Estimation of the dietary requirement for vitamin D in healthy adults. Am J Clin Nutr. 2008;88(6):1535-42. 4. Cashman KD, Fitzgerald AP, Kiely M, Seamans KM. A systematic review and meta-regression analysis of the vitamin D intake-serum 25-hydroxyvitamin D relationship to inform European recommendations. Br J Nutr. 2011;106(11):1638-48. 5. Crowe FL, Steur M, Allen NE, et al. Plasma concentrations of 25-hydroxyvitamin D in meat eaters, fish eaters, vegetarians and vegans: results from the EPIC-Oxford study. Public Health Nutr. 2011;14(2):340-6. 6. Cannell JJ, Grant WB, Holick MF. Vitamin D and inflammation. Dermato-Endocrinology. 2014;6(1):e983401-1-10.<br> 7. Rebel H, der Spek CD, Salvatori D, et al.UV exposure inhibits intestinal tumour growth and progression to malignancy in intestine-specific Apc mutant mice kept on low vitamin D diet. Int J Cancer. 2015;136(2):271-7. 8. Zivadinov R, Treu CN, Weinstock-Guttman B, et al. Interdependence and contributions of sun exposure and vitamin D to MRI measures in multiple sclerosis. J Neurol Neurosurg Psychiatry. 2013;84(10):1075-81. 9. Opländer C, Volkmar CM, Paunel-Görgülü A, et al. Whole body UVA irradiation lowers systemic blood pressure by release of nitric oxide from intracutaneous photolabile nitric oxide derivates. Circ Res. 2009;105(10):1031-40. 10. Ensrud KE, Ewing SK, Fredman L, et al. Circulating 25-hydroxyvitamin D levels and frailty status in older women. J Clin Endocrinol Metab. 2010;95(12):5266-73. 11. Ensrud KE, Blackwell TL, Cauley JA, et al. Circulating 25-hydroxyvitamin D levels and frailty in older men: the osteoporotic fractures in men study. J Am Geriatr Soc. 2011;59(1):101-6. 12. Wang L, Song Y, Manson JE, et al. Circulating 25-hydroxy-vitamin D and risk of cardiovascular disease: A meta-analysis of prospective studies. Circ Cardiovasc Qual Outcomes. 2012;5(6):819-29. 13. Garland CF, Kim JJ, Mohr SB, et al. Meta-analysis of all-cause mortality according to serum 25-hydroxyvitamin D. Am J Pub Health. 2014;104(8):e43-50. 14. Vieth R. Implications for 25-hydroxyvitamin D testing of public health policies about the benefits and risks of vitamin D fortification and supplementation. Scand J Clin Lab Invest Suppl. 2012;243:144-53.

Disclosure I receive funding from Bio-Tech Pharmacal, Inc. (Fayetteville, AR), MediSun Technology (Highland Park, IL), and the Vitamin D Council (San Luis Obispo, CA).

On 2015 Feb 25, Ivan Oransky commented:

Following a great deal of criticism of this article, the journal issued a statement of concern and then reclassified the paper as "opinion." http://retractionwatch.com/2015/02/24/frontiers-lets-hiv-denier-article-stand-reclassifies-it-as-opinion/

On 2015 Oct 22, Alan Fairlamb commented:

This is an excellent and comprehensive review of the prospects for elimination of Gambiense HAT. A number of uncertainties are identified and important research questions highlighted. However, one posible threat not considered is the risk of drug resistance emerging to the limited armamentarium of drugs available to treat patients and thereby reduce transmission. Drug susceptibility testing of clinical isolates would be useful in defining optimal treatment regimens.

Antimicrob Agents Chemother. 2010 Jul;54(7):2893-900. doi: 10.1128/AAC.00332-10. Epub 2010 May 3.

On 2015 Apr 21, Helmi BEN SAAD commented:

A letter to the Editor, highlighting some methodological problems in the above article is now published: http://www.libyanjournalofmedicine.net/index.php/ljm/article/view/27760

H Ben Saad. Methodological problems in the article comparing lung function profiles and aerobic capacity of adult cigarette and hookah smokers after 12 weeks intermittent training.Libyan J Med 2015, 10: 27760 - http://dx.doi.org/10.3402/ljm.v10.27760

On 2016 Jul 14, Andrea Fuso commented:

The analysis was initially made on these two genes since those are the genes we were studying in relation to muscle differentiation (myogenin) and Alzheimer's Disease (PSEN1). In these two models we gained in the years sufficient knowledge to finely modulate methylation and to foresee that different treatments correspond to differential methylation. Moreover, we are interested in "rapid" methylation changes and it is our hypothesis that genes without CpG islands can be modulated by dynamic changes in DNA methylation that are more rapid than in CpG islands (in wich methylation-dependent silencing/activation is more stable) and possible also in non replicating tissues (brain). We are now checking promoters with and without CpG islands. Of course, designing MIPs in CpG islands could be very difficult or even impossible. That's a limitation.

On 2016 Jul 14, Long-Cheng Li commented:

Dear Andrea,

I am sorry for not having not responded earlier and thank you for your reply.

If the possibility of incomplete conversion can be excluded as you have explained above, I think the findings in your work is significant in that they makes researchers better aware of the non-CpG methylatioon issue. I do have another comment though which is why you chose two genes (myogenin and PSEN1) without CpG islands in their promoters instead of genes with CpG islands where differential methylation often occurs.

On 2016 Jul 13, Andrea Fuso commented:

None

On 2016 Jul 13, Andrea Fuso commented:

Dear Long-Cheng, thank you for your critic comments. Discussing this issue is very important and I'm sincerely happy you took some time to read our manuscript and share your thoughts. When we published the paper, we were hopeful it could raise some discussion useful to a better understanding of the non-CpG issue.

First of all, I would like to emphasize that our paper was not a criticism of MethPrimer. As a matter of fact (as disclosed in the paper) different primer design softwares, not just “MethPrimer”, allow to design bisulfite primers based on the assumption that non-CpG cytosines are transformed. MethPrimer is simply the most used and known and we defined “methprimers” the oligo designed using these different softwares. Our criticism were, on the contrary, addressed toward the concept that stands at the base of all these primer design softwares: i.e. that non-CpG cytosines are (almost) always demethylated. The idea of releasing MethPrimer was great and in line with the widely accepted concept of that era on non-CpG methylation. We should now critically consider that concept and make some effort to better understand extension and significance of non-CpG methylation and, in case, revise our tools for the study of DNA methylation. The adaptation of MethPrimer to the picking of primers in regions with few cytosines goes in this way and it is highly appreciable.

As for your comments about incomplete conversion: your considerations are correct but you are not correct when you affirm that “no efforts were made to verify the completeness of bisulfite conversion of the template DNA”. If you look at the methods and at the previous papers cited in the methods (previously published description were not repeated and just cited) you can see that we took many efforts to demonstrate that our analysis was not affected by artifacts. Our studies on myogenin methylation (some years ago) started with classical bisulphite conversion (no kits) but in the years we started to place side by side classical and kit-assisted bisulphite conversion, obtaining comparable results. The present study was made by using the Qiagen Epitect Kit but specific (high and low methylated samples) controls were modified using the ZymoResearch kit and the in-lab prepared bisulphite. These controls were real samples, not just PCR products. According to your idea that our data could be due to incomplete conversion, you should explain why incomplete conversion occurs only (or mainly) for high methylated DNA but not in low methylated DNA, since the difference between methprimers and MIPs is less when analyzing low methylated samples. In our analyses, in which samples with different (expected) methylation levels are modified in the same run, we can indeed observe both methylated and unmethylated sequences, according to the expected methylation. I think that this observation, more than any “control” witness the quality of the bisulphite conversion we make. If you suggest, or suspect, that bisulphite conversion kit (like the Qiagen and the Zymoresearch) that are today used in almost all the methylation studies, and that are preferred to the in-lab prepared bisulphite just to guarantee reliability and avoid incomplete conversion, are responsible for incomplete conversion….well, the problem is much bigger. I will be happy if you and others want to add more to this interesting discussion.

In conclusion, I completely agree with you that much more care should be put in the control of the bisulphite analysis…and as a reviewer of papers dealing with DNA methylation, I can see that few researchers take care of performing rigorous controls. But, I also invite you and the other colleagues to consider that new and unexpected results, such as relevant non-CpG methylation, deserve to be considered with unbiased attitude and methods.

On 2016 Jul 04, Long-Cheng Li commented:

As the author of MethPrimer, I thank the authors of this paper for looking into the bias issue of our program. However the conclusion reached that "MethPrimers can result in underestimation of the high methylation levels eventually biasing the detection of differences" could be misleading based on the following reasons:

1) MethPrimer was developed in an era when there was little knowledge about the existence of non-CpG methylation and under the assumption that all non-CpG cytosines are not methylated. One of the important principles used by MethPrimer in picking primers is to select primers that preferentially amplify bisulfite converted DNA, given the inherent issue of incomplete conversion of unmethylated cytosines during bisulfite treatment. This is implemented by forcing picking primers in regions which must contain a minimum number of non-CpG cytosines.

2) Using “methylation-insensitive primers” (MIPs) in which non-CpG Cs are degenerated, the authors detected higher levels of methylation compared to primers designed by MethPrimer in the promoter regions of two mouse genes (myogenin and PSEN1). However, no efforts were made to verify the completeness of bisulfite conversion of the template DNA. Although control samples with complete methylated and unmethylated DNA were included in the analysis, the use of PCR products as a control for unmethylated DNA is problematic since incomplete conversion is less an issue for PCR products compared to genomic DNA. In other words, complete conversion of the control DNA does not necessarily mean that genomic DNA was also completely converted. If that were true, the non-CpG methylation detected could be merely an artifact.

I do caution that researchers should keep in mind potential non-CpG methylation. Before more evidence is available about the prevalence of non-CpG methylation and its function, researchers should care more about potential incompleteness of bisulfite conversion and subsequent overestimation of methylation levels in the DNA.

On 2015 Apr 23, Janet Kern commented:

Because of differences noted between the study conclusion and the results, on February 24, 2015, an email was sent to Dr. Hewitson requesting the dataset. However, to date, the authors have ignored repeated requests for the dataset.

On 2015 Feb 21, Dan Laks commented:

None

On 2015 Dec 12, Donald Forsdyke commented:

LESS BP MEDICATION NEEDED IN HOT WEATHER This paper recommends “More aggressive blood pressure lowering treatment in the cold months … in high risk individuals” (1), which implies less aggressive blood pressure (BP) lowering treatment in hot months. Indeed, a well-documented “J-curve” observation is that, below a certain value, BP lowering is harmful – e.g. acute kidney injury (2). Quite rightly, the cartoon in the accompanying editorial has question marks at both the high and low ends of the temperature scale (3). However, the paper’s focus is on more treatment in winter, not on less treatment in summer, and it only scores the deaths attributed to cardiovascular disease (CVD), a number that declines in hot weather (1). Cases where mortality can be attributed to other causes are excluded.

Regarding CVD it is reported that “The excess risk was similar between people treated with blood pressure lowering agents and those without” (1). But given the widely different mechanisms of action of different BP lowering agents, surely this statement needs backing with more information on agents and their dosages? Large summertime systolic BP declines that mandate treatment adjustment are not uncommon (4). Differential responses in hot weather can depend on type and dosage of antihypertensive medication. Indeed, extrapolation from the supplementary plot (Fig 1) of Yang et al. (2015), the BP would be normal at 40°C and medication could be dispensed with (1). Taking medication at that temperature could be lethal (5). Indeed, a Canadian case study with an angiotensin receptor blocker found that medication could be dispensed with when summer temperatures reached 33°C (6).

It is obvious from Fig. 3 that the statement that “the seasonal variation in blood pressure … was abolished by the use of home central heating” (1), is incorrect. In Harbin province, where winter temperatures are similar to those in Canada, there is less BP increase in cold weather than in other provinces, and this is attributed to central heating. But the seasonal BP increase is clearly not abolished. Despite central heating, in the Canadian case study the BP decline for a 10°C increase in temperature was of the order of 20 mm Hg (6) – a far higher value than the 6 mm Hg reported here (1).

1 Yang L, Li L, Lewington S. Guo Y, Sherliker P, Bian Z, Collins R, et al (2015) Outdoor temperature, blood pressure, and cardiovascular disease mortality among 23000 individuals with diagnosed cardiovascular diseases from China. Eur Heart J 36:1178-1185. Yang L, 2015

2 Tomlinson LA, Abel GA, Chaudhry AN, Tomson CR, Wilkinson IB, Roland MO et al (2013) ACE inhibitor and angiotensin-II receptor antagonist prescribing and hospital admissions with acute kidney injury: a longitudinal ecological study. PLoS One 8:e78465.Tomlinson LA, 2013

3 Bruno RM, Taddei S (2015) ‘Tis bitter cold and I am sick at heart’: establishing the relationship between outdoor temperature, blood pressure, and cardiovascular mortality. Eur Heart J 36:1152-1154.Bruno RM, 2015

4 Stergiou GS, Myrsilidi A, Kollias A, Destounis A, Roussias L, Kalogeropoulos P (2015) Seasonal variation in meteorological parameters and office, ambulatory and home blood pressure: predicting factors and clinical implications. Hypertension Research 38(12):869-875. Stergiou GS, 2015

5 Editorial (2015) Health professionals: be prepared for heatwaves. Lancet 386:219. Anonymous, 2015

6 Forsdyke DR (2015) Summertime dosage-dependent hypersensitivity to an angiotensin II receptor blocker. BMC Res Notes 8:227. Forsdyke DR, 2015

On 2015 Feb 18, Hilda Bastian commented:

This study states as its objective "to determine the efficacy and safety of varenicline" for quitting smoking via smoking reduction. The authors point out that one limitation of the study is its generalizability to a broad population, given its stringent and extensive exclusion criteria. However, it does not stress that both this, and the size of the study, very much preclude this single study "determining" safety of varenicline. The findings in relation to serious adverse events need to be considered in the light of the lower risk for serious adverse events in this study population.

The paper does not refer readers to the safety warnings and concerns about varenicline issued by both the US FDA and European Medicines Agency (EMA), in relation both to psychiatric (FDA boxed warning) and cardiovascular events (FDA, 2012)(see also EMA). (Readers may also be interested in Singh S, 2011 on the issue of cardiovascular events.)

UPDATE: On 9 March 2015, the FDA reviewed safety data on varenicline, retaining the boxed safety warning, and including a warning on interaction with alcohol. However, in March a large meta-analysis found that varenicline increased insomnia and bad dreams, but not depression, suicide, or suicidal ideation (Thomas KH, 2015).

In terms of effectiveness, the authors rightly raise the issue of a lack of direct comparisons between varenicline and others options for smoking reduction. Readers might be interested in Asfar T, 2011, which finds that nicotine replacement therapy (NRT) achieved smoking reduction rates that were not dramatically dissimilar. Cahill K, 2010 found some (inconclusive) evidence that NRT and varenicline result in similar quit rates. Nor are pharmacological means the only successful options for reducing smoking without the risk of serious adverse events.

Note also that this study was funded by Pfizer, manufacturer of the varenicline product marketed as Chantix in the US (Champix in Europe).

On 2015 Feb 21, William Grant commented:

Outdoor workers have better health outcomes due to UVB exposure

The paper by Bauer and colleagues recommended that outdoor workers reduce their UV radiation exposure in order to reduce their risk of squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) [1]. Overlooked in this paper was any discussion of the health benefits of UV exposure through outdoor work.

Solar UVB exposure reduces risk of many types of cancer as shown in geographical ecological studies from Australia, China, France, Japan, Spain, and the United States [2]. Deaths due to internal cancers are much higher than those due to non-melanoma skin cancer [3]. Solar UVB exposure is the primary source of vitamin D for most people, and there are many health outcomes linked inversely to 25-hydroxyvitamin D concentrations [4].

Perhaps most relevant for Germany is a study of cancer incidence rates with respect to occupation in Nordic countries [5]. Using a data base of nearly three million cancer incidence cases for 54 occupation categories [6], an index of UVB exposure was developed, namely, lip cancer incidence rate less lung cancer incidence rate for males. Fourteen types of cancer were significantly inversely correlated with this index for males, but only three for females. Since females wear lipstick, an independent index could not be developed for them. Interestingly, this index was inversely correlated with incidence of non-melanoma skin cancer as well as melanoma for males.

Furthermore, a study in Denmark found "Mortality was reduced among patients with BCC (10-year MRR = 0.91 (95% CI: 0.89-0.92) and did not vary by age, comorbidity, or socioeconomic status. Mortality among patients with SCC was increased and varied by age, selected chronic diseases, but not socioeconomic status." [7]. Since smoking is a risk factor for SCC [8], the finding of an increased risk of death associated with SCC is not surprising since it is also an important risk factor for many types of cancer [2] as well as cardiovascular disease and other diseases.

Since skin pigmentation has adapted to where people have lived for many generations to both reduce the adverse effects of solar UVB as well as to produce sufficient vitamin D for optimal health [9,10], it is not clear that undue protection against solar UVB exposure is warranted. However, erythema is best avoided.

References 1. Bauer A, Beissert S, Knuschke P. [Prevention of occupational solar UV radiation-induced epithelial skin cancer.] Hautarzt. 2015 Feb 17. [Epub ahead of print] 2. Moukayed M, Grant WB. Molecular link between vitamin D and cancer prevention. Nutrients. 2013;5(10):3993-4023. 3. Grant WB. In defense of the sun: An estimate of changes in mortality rates in the United States if mean serum 25-hydroxyvitamin D levels were raised to 45 ng/mL by solar ultraviolet-B irradiance. Dermatoendocrinol. 2009;1(4):207-14. 4. Pludowski P, Holick MF, Pilz S, et al. Vitamin D effects on musculoskeletal health, immunity, autoimmunity, cardiovascular disease, cancer, fertility, pregnancy, dementia and mortality- a review of recent evidence. Autoimmun Rev. 2013;12(10):976-89. 5. Grant WB. Role of solar UV irradiance and smoking in cancer as inferred from cancer incidence rates by occupation in Nordic countries. Dermatoendocrinol. 2012;4(2):203-11. 6. Pukkala E, Martinsen JI, Lynge E, et al. Occupation and cancer—follow-up of 15 million people in five Nordic countries. Acta Oncol 2009;48:646-790; 7. Jensen AØ, Lamberg AL, Jacobsen JB, et al. Non-melanoma skin cancer and ten-year all-cause mortality: a population-based cohort study. Acta Derm Venereol. 2010;90(4):362-7. 8. Leonardi-Bee J, Ellison T, Bath-Hextall F. Smoking and the risk of nonmelanoma skin cancer: systematic review and meta-analysis. Arch Dermatol. 2012;148(8):939-46. 9. Yuen AW, Jablonski NG. Vitamin D: in the evolution of human skin colour. Med Hypotheses. 2010;74(1):39-44. 10. Jablonski NG, Chaplin G. Colloquium paper: human skin pigmentation as an adaptation to UV radiation. Proc Natl Acad Sci U S A. 2010;107 Suppl 2:8962-8.

Disclosure I receive funding from Bio-Tech Pharmacal, Inc. (Fayetteville, AR), MediSun Technology (Highland Park, IL), and the Vitamin D Council (San Luis Obispo, CA).

On 2015 Feb 24, Amanda Capes-Davis commented:

Are the authors able to comment further on the cell lines used in this study, to confirm that results are not related to the cell culture models used?

The Materials and Methods section states that cell lines (MCF-7, MCF-10A and BT549) were obtained from the ATCC and authenticated before purchase. I am very pleased to see information included on source and previous testing. However, it is not clear how long ago testing was performed. In some cases, cell lines are used by many different laboratory members and may be passed from laboratory to laboratory. That gives time for cross-contamination or other cell culture problems to arise. Mycoplasma contamination, or cross-contamination by another cell line, might result in behavioral changes at the time that morphine is introduced.

The results here have significant clinical implications, suggesting that pain control in breast cancer may contribute to chemoresistance. So it is essential to ensure that cell culture models are tested to eliminate any possibility of artefacts.

I particularly raise this issue because, as the authors note in their Discussion, previous studies have suggested that morphine decreases cell proliferation in many cancer cell types.

The International Cell Line Authentication Committee (ICLAC) has released a checklist that sets out cell line reporting requirements for manuscripts and grant applications. The checklist can be found at http://iclac.org/resources/cell-line-checklist/.

On 2015 Sep 16, Geriatric Medicine Journal Club commented:

Sleep disturbances are common in the elderly and adversely affect quality of life. Pharmacotherapy is often limited by lack of efficacy and/or adverse events. This article was critically appraised at the May 2015 Geriatric Medicine Journal Club (follow #GeriMedJC on Twitter). The full discussion can be found at: http://gerimedjc.blogspot.com/2015/05/may-2015-gerimedjc.html?spref=tw While mindfulness meditation seems to improve sleep quality in older adults, the challenge is how to operationalize this type of intervention.

On 2017 Mar 05, Atanas G. Atanasov commented:

Very good overview on the health-modulating potential of mushrooms. I have highlighted this review on: http://healthandscienceportal.blogspot.com/2017/03/mushrooms-for-improvement-of-health-and.html

On 2015 Feb 15, Jinlei Nie commented:

In RESULTS: "not significant", but and "P<0.05"???

On 2015 Jun 18, Elsamma Chacko commented:

Exercise before breakfast increases hepatic glucose production and glucose levels can go up.

On 2016 Apr 18, Tom Kindlon commented:

James C Coyne PhD has blogged here https://jcoynester.wordpress.com/2016/03/20/why-the-cochrane-collaboration-needs-to-clean-up-conflicts-of-interest/ about my comment:

"Selective reporting (outcome bias)" and White et al. (2011) I don't believe that White et al. (2011) (the PACE Trial) (3) should be classed as having a low risk of bias under "Selective reporting (outcome bias)" (Figure 2, page 15). According to the Cochrane Collaboration's tool for assessing risk of bias (21), the category of low risk of bias is for: "The study protocol is available and all of the study’s pre-specified (primary and secondary) outcomes that are of interest in the review have been reported in the pre-specified way". This is not the case in the PACE Trial. The three primary efficacy outcomes can be seen in the published protocol (22). None have been reported in the pre-specified way. The Cochrane Collaboration's tool for assessing risk of bias states that a “high risk” of bias applies if any one of several criteria are met, including that “not all of the study’s pre-specified primary outcomes have been reported” or “one or more primary outcomes is reported using measurements, analysis methods or subsets of the data (e.g. subscales) that were not pre-specified”. In the PACE Trial, the third primary outcome measure (the number of "overall improvers") was never published. Also, the other two primary outcome measures were reported using analysis methods that were not pre-specified (including switching from the bimodal to the Likert scoring method for The Chalder Fatigue Scale, one of the primary outcomes in your review). These facts mean that the “high risk of bias” category should apply.

and the response I received from one of the authors .

On 2015 Sep 14, Tom Kindlon commented:

None

On 2016 Jun 07, Tom Kindlon commented:

None

On 2015 Sep 14, Tom Kindlon commented:

(contd.)

11 National Institute for Health and Clinical Excellence. Chronic fatigue syndrome/myalgic encephalomyelitis (or encephalopathy): diagnosis and management of CFS/ME in adults and children, 2007. http://www.nice.org.uk/guidance/CG53 Accessed September 6, 2015. London: National Institute for Health and Clinical Excellence.

12 White PD, Goldsmith KA, Johnson AL, Potts L, Walwyn R, DeCesare JC, et al. Comparison of adaptive pacing therapy, cognitive behaviour therapy, graded exercise therapy, and specialist medical care for chronic fatigue syndrome (PACE): a randomised trial. The Lancet 2011;377:823-36.

13 Kindlon T. PACE Trial - 97% of the participants who didn't have a psychiatric disorder satisfied the definition of M.E. used. https://listserv.nodak.edu/cgi-bin/wa.exe?A2=ind1106A&L=CO-CURE&P=R2764 Accessed: September 6, 2015

14 Ellen Goudsmit on PubMed Commons: http://www.ncbi.nlm.nih.gov/myncbi/ellen m.goudsmit.1/comments/

15 Green CR, Cowan P, Elk R, O'Neil KM, Rasmussen AL. National Institutes of Health Pathways to Prevention Workshop: advancing the research on myalgic encephalomyelitis/chronic fatigue syndrome. Ann Intern Med. 2015; 162:860-5.

16 Haney E, Smith MEB, McDonagh M, Pappas M, Daeges M, Wasson N, et al. Diagnostic methods for myalgic encephalomyelitis/chronic fatigue syndrome: a systematic review for a National Institutes of Health Pathways to Prevention Workshop. Ann Intern Med. 2015; 162:834-40.

17 Smith MEB, Haney E, McDonagh M, Pappas M, Daeges M, Wasson N, et al. Treatment of myalgic encephalomyelitis/chronic fatigue syndrome: a systematic review for a National Institutes of Health Pathways to Prevention Workshop. Ann Intern Med. 2015; 162:841-50.

On 2015 Sep 14, Tom Kindlon commented:

Comment 2 of 2 formally submitted on September 9, 2015 using instructions here: http://www.cochranelibrary.com/help/submitting-comments-on-cochrane-reviews.html

(This is available in one piece at: http://forums.phoenixrising.me/index.php?threads/my-two-detailed-comments-on-the-cochrane-exercise-therapy-for-cfs-review-2015.39801/ )

Second comment:

I have decided to split my comment into two as it was getting very long. This is part two.

Variation in interventions

It would have been useful to have some more information on the “exercise with pacing” intervention tested in the Wallman et al. (2004) trial and how it was distinct from some other exercise interventions tested. The authors say (1): “On days when symptoms are worse, patients should either shorten the session to a time they consider manageable or, if feeling particularly unwell, abandon the session altogether” (p. 143). I don't believe the description given in the review conveys this. In the review, this approach is described as "Exercise with pacing: exercise in which the incremental increase in exercise was personally set." But Wallman et al.’s approach allows patients to decrease as well as increase how much exercise they do on the day. This approach also contrasts with how White (an investigator in two of the trials) has described graded exercise therapy: "if [after increasing the intensity or duration of exercise] there has been an increase in symptoms, or any other adverse effects, they should stay at their current level of exercise for a further week or two, until the symptoms are back to their previous levels" (2). In the PACE Trial manual White co-wrote (3), the GET intervention was guided by the principle that “planned physical activity and not symptoms are used to determine what the participant does” (p. 21); similarly, “it is their planned physical activity, and not their symptoms, that determine what they are asked to do” (p. 20). Compliance data would help us examine which approach patients are actually using: I suspect many patients are in fact doing exercise with pacing even in trials such as the PACE Trial (i.e. when they have increased symptoms, often reducing levels of exercise and sometimes doing no exercise activities at all on that day).

Bimodal versus Likert scoring in Wearden et al. (2010)

I find it odd that the fatigue scores for the Wearden et al. (2010) trial (4) are given in the 0-33 format rather than the 0-11 scoring method. The 0-11 scoring system is what is mentioned as a primary outcome measure in the protocol and is what is reported in the main paper reporting the results (4, 5). It is even what your own report says on p. 44 is the scoring method (“Fatigue Scale, FS; 11 items; each item was scored dichotomously on a 4-point scale [0, 0, 1 or 1]”). This is important because using the scoring method for which you don't report data (0-11), there is no statistically significant difference at the primary outcome point of 70 weeks (5).

Diagnostic criteria

One problem with using these trials as an evidence base, which I don't believe was mentioned, is that all the trials used the Oxford and Fukuda diagnostic criteria (6, 7). Neither of these criteria require patients to have post-exertional malaise (or something similar). Many consider this to be a core symptom of ME/CFS and it is mandatory in most of the other major criteria (8-11). [Aside: The London criteria were assessed in the PACE Trial (12) but they seem to have been operationalised in an unusual way. Ninety seven per cent of the participants who satisfied the (broad) Oxford criteria who didn't have a psychiatric disorder satisfied the definition of M.E. used (13). Ellen Goudsmit, one of the authors of the London criteria, has rejected the way they were used in the PACE Trial (14)]. So this lack of requirement for patients to have post-exertional malaise (or a similar description) means we cannot be sure that the evidence can be generalised to such patients. An independent National Institutes of Health committee this year concluded "continuing to use the Oxford definition may impair progress and cause harm. Therefore, for progress to occur, we recommend that this definition be retired" (15). An Agency for Healthcare Research and Quality review of diagnostic methods this year reached a similar conclusion: "Consensus groups and researchers should consider retiring the Oxford case definition because it differs from the other case definitions and is the least restrictive, probably including individuals with other overlapping conditions” (16). An Agency for Healthcare Research and Quality review of ME/CFS treatments said: "The Oxford CFS case definition is the least restrictive, and its use as entry criteria could have resulted in selection of participants with other fatiguing illnesses or illnesses that resolve spontaneously with time" (17).

Exclusion of some data from analyses due to baseline differences

It seems unfortunate that some data cannot be used due to baseline differences e.g. "Four trials (669 participants) contributed data for evaluation of physical functioning at follow-up (Jason 2007; Powell 2001; Wearden 2010; White 2011). Jason 2007 observed better results among participants in the relaxation group (MD 21.48, 95% CI 5.81 to 37.15). However, results were distorted by large baseline differences in physical functioning between the exercise and relaxation groups (39/100 vs 54/100); therefore we decided not to include these results in the meta-analysis". It would be good if other methods could be investigated (e.g. using baseline levels as covariates) to analyse such data.

Thank you for taking the time to read my comments.

Tom Kindlon

Conflict of Interest statement:

I am a committee member of the Irish ME/CFS Association and do a variety of unpaid work for the Association.

References

1 Wallman KE, Morton AR, Goodman C, Grove R. Exercise prescription for individuals with chronic fatigue syndrome. Med J Aust. 2005;183:142-3.

2 White P. How exercise can help chronic fatigue syndrome. Pulse: 1998. June 20:86-87.

3 Bavinton J, Darbishire L, White PD -on behalf of the PACE trial management group. Graded Exercise Therapy for CFS/ME (Therapist Manual) http://www.pacetrial.org/docs/get-therapist-manual.pdf

4 Wearden AJ, Riste L, Dowrick C, Chew-Graham C, Bentall RP, Morriss RK, Peters S, Dunn G, Richardson G, Lovell K, Powell P. Fatigue Intervention by Nurses Evaluation--the FINE Trial. A randomised controlled trial of nurse led self-help treatment for patients in primary care with chronic fatigue syndrome: study protocol. [ISRCTN74156610]. BMC Med. 2006 Apr 7;4:9.

5 Wearden AJ, Dowrick C, Chew-Graham C, Bentall RP, Morriss RK, Peters S, Riste L, Richardson G, Lovell K, Dunn G; Fatigue Intervention by Nurses Evaluation (FINE) trial writing group and the FINE trial group. Nurse led, home based self help treatment for patients in primary care with chronic fatigue syndrome: randomised controlled trial. BMJ. 2010 Apr 23;340:c1777. doi: 10.1136/bmj.c1777.

6 Sharpe M, Archard L, Banatvala J, Borysiewicz LK, Clare AW, David A, et al. Chronic fatigue syndrome: guidelines for research. Journal of the Royal Society of Medicine 1991;84 (2):118–21.

7 Fukuda K, Straus SE, Hickie I, et al. The chronic fatigue syndrome: A comprehensive approach to its definition and study. Ann Intern Med. 1994; 121: 953‑959.

8 Carruthers BM, Jain AK, De Meirleir KL, et al. Myalgic Encephalomyelitis/chronic fatigue syndrome: Clinical working case definition, diagnostic and treatments protocols. Journal of Chronic Fatigue Syndrome. 2003; 11: 7-115.

9 Carruthers BM, van de Sande MI, De Meirleir KL, et al. Myalgic encephalomyelitis: International Consensus Criteria. J Intern Med. 2011; 270: 327-338.

10 IOM (Institute of Medicine). Beyond myalgic encephalomyelitis/chronic fatigue syndrome: Redefining an illness. Washington, DC: The National Academies; 2015.

(continues)

On 2015 Sep 14, Tom Kindlon commented:

(continues)

References:

1 Turner L, Boutron I, Hróbjartsson A, Altman DG, Moher D: The evolution of assessing bias in Cochrane systematic reviews of interventions: celebrating methodological contributions of the Cochrane Collaboration. Syst Rev 2013, 2:79.

2 Chalder T, Goldsmith KA, White PD, Sharpe M, Pickles AR. Rehabilitative therapies for chronic fatigue syndrome: a secondary mediation analysis of the PACE trial. Lancet Psychiatry. 2015;2:141-152.

3 White PD, Goldsmith KA, Johnson AL, Potts L, Walwyn R, DeCesare JC, et al. Comparison of adaptive pacing therapy, cognitive behaviour therapy, graded exercise therapy, and specialist medical care for chronic fatigue syndrome (PACE): a randomised trial. The Lancet 2011;377:823-36.

4 Kindlon T. Reporting of Harms Associated with Graded Exercise Therapy and Cognitive Behavioural Therapy in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Bull IACFS ME. 2011;19:59-111. http://iacfsme.org/ME-CFS-Primer-Education/Bulletins/BulletinRelatedPages5/Reporting-of-Harms-Associated-with-Graded-Exercise.aspx

5 Lipkin DP, Scriven AJ, Crake T, Poole-Wilson PA (1986). Six minute walking test for assessing exercise capacity in chronic heart failure. British Medical Journal 292, 653-5.

6 Kadikar A, Maurer J, Kesten S. The six-minute walk test: a guide to assessment for lung transplantation. J Heart Lung Transplant. 1997 Mar;16(3):313-9.

7 Friedberg F, Sohl S. Cognitive-behavior therapy in chronic fatigue syndrome: is improvement related to increased physical activity? J Clin Psychol. 2009 Feb 11.

8 Friedberg F. Does graded activity increase activity? A case study of chronic fatigue syndrome. Journal of Behavior Therapy and Experimental Psychiatry, 2002, 33, 3-4, 203-215

9 Results and In-depth Analysis of the 2012 ME Association Patient Survey Examining the Acceptability, Efficacy and Safety of Cognitive Behavioural Therapy, Graded Exercise Therapy and Pacing, as Interventions used as Management Strategies for ME/CFS. Gawcott, England. http://www.meassociation.org.uk/2015/05/23959/ Accessed: September 3, 2015

10 Critical Illness - A Dreadful Experience with Scottish Provident. http://forums.moneysavingexpert.com/showthread.php?t=2356683 Accessed: September 4, 2015

11 McCrone P, Sharpe M, Chalder T, Knapp M, Johnson AL, Goldsmith KA, White PD. Adaptive pacing, cognitive behaviour therapy, graded exercise, and specialist medical care for chronic fatigue syndrome: a cost-effectiveness analysis. PLoS One. 2012;7(8):e40808.

12 Rapport d’évaluation (2002-2004) portant sur l’exécution des conventions de rééducation entre le Comité de l’assurance soins de santé (INAMI) et les Centres de référence pour le Syndrome de fatigue chronique (SFC). 2006. http://health.belgium.be/internet2Prd/groups/public/@public/@shc/documents/ie2divers/14926531_fr.pdf (Starts on page 223.) Accessed September 4, 2015 (French language edition)

13 Evaluatierapport (2002-2004) met betrekking tot de uitvoering van de revalidatieovereenkomsten tussen het Comité van de verzekering voor geneeskundige verzorging (ingesteld bij het Rijksinstituut voor Ziekte- en invaliditeitsverzekering) en de Referentiecentra voor het Chronisch vermoeidheidssyndroom (CVS). 2006. http://health.belgium.be/internet2Prd/groups/public/@public/@shc/documents/ie2divers/14926531.pdf (Starts on page 227.) Accessed September 4, 2015 (Dutch language version)

14 Stordeur S, Thiry N, Eyssen M. Chronisch Vermoeidheidssyndroom: diagnose, behandeling en zorgorganisatie. Health Services Research (HSR). Brussel: Federaal Kenniscentrum voor de Gezondheidszorg (KCE); 2008. KCE reports 88A (D/2008/10.273/58) https://kce.fgov.be/sites/default/files/page_documents/d20081027358.pdf Accessed September 4, 2015

15 Wiborg JF, Knoop H, Stulemeijer M, Prins JB, Bleijenberg G. How does cognitive behaviour therapy reduce fatigue in patients with chronic fatigue syndrome? The role of physical activity. Psychol Med. 2010; 40:1281-1287.

16 Van Kessel K, Moss-Morris R, Willoughby, Chalder T, Johnson MH, Robinson E, A randomized controlled trial of cognitive behavior therapy for multiple sclerosis fatigue, Psychosom. Med. 2008; 70:205–213.

17 Powell P. FINE Trial Patient Booklet http://www.fine-trial.net/downloads/Patient PR Manual ver9 Apr05.pdf Accessed September 7, 2015

18 Twisk FNM, Maes M. A review on Cognitive Behavorial Therapy (CBT) and Graded Exercise Therapy (GET) in Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS): CBT/GET is not only ineffective and not evidence-based, but also potentially harmful for many patients with ME/CFS. Neuro Endocrinol Lett. 2009;30:284-299.

19 Carruthers BM et al. Myalgic Encephalomyelitis – Adult & Paediatric: International Consensus Primer for Medical Practitioners. ISBN 978-0-9739335-3-6 http://www.investinme.org/Documents/Guidelines/Myalgic Encephalomyelitis International Consensus Primer -2012-11-26.pdf Accessed September 5, 2015

20 Twisk FN. Objective Evidence of Post-exertional “Malaise” in Myalgic Encephalomyelitis and Chronic Fatigue Syndrome. J Sports Med Doping Stud 2015. 5:159. doi: 10.4172/2161-0673.1000159

21 Higgins JPT, Green S: Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. Table 8.5.d. The Cochrane Collaboration; 2011. http://handbook.cochrane.org/chapter_8/table_8_5_d_criteria_for_judging_risk_of_bias_in_the_risk_of.htm Accessed: September 5, 2015

22 White PD, Sharpe MC, Chalder T, DeCesare JC, Walwyn R; on behalf of the PACE trial group. Protocol for the PACE trial: A randomised controlled trial of adaptive pacing, cognitive behaviour therapy, and graded exercise as supplements to standardised specialist medical care versus standardised specialist medical care alone for patients with the chronic fatigue syndrome/myalgic encephalomyelitis or encephalopathy. BMC Neurology 2007, 7:6 http://www.biomedcentral.com/1471-2377/7/6 Accessed: September 5, 2015

On 2015 Sep 14, Tom Kindlon commented:

(contd.)

Compliance

The review doesn't include any information on compliance. I'm not sure that there is much published information on this but I know there was a measure based on attendance at therapy sessions (which could be conducted over the phone) given for the PACE Trial (3). Ideally, it would be interesting if you could obtain some unpublished data from activity logs, records from heart-rate monitors, and other records to help build up a picture of what exercise was actually performed and the level of compliance. Information on adherence and what exercise was actually done is important in terms of helping clinicians, and indeed patients, to interpret and use the data. I mention patients because patients' own decisions about their behaviour is likely to be affected by the medical information available to them, both within and outside of a supervised programme of graded exercise; unlike with an intervention like a drug, patients can undertake exercise without professional supervision.

"Selective reporting (outcome bias)" and White et al. (2011)

I don't believe that White et al. (2011) (the PACE Trial) (3) should be classed as having a low risk of bias under "Selective reporting (outcome bias)" (Figure 2, page 15). According to the Cochrane Collaboration's tool for assessing risk of bias (21), the category of low risk of bias is for: "The study protocol is available and all of the study’s pre-specified (primary and secondary) outcomes that are of interest in the review have been reported in the pre-specified way". This is not the case in the PACE Trial. The three primary efficacy outcomes can be seen in the published protocol (22). None have been reported in the pre-specified way. The Cochrane Collaboration's tool for assessing risk of bias states that a “high risk” of bias applies if any one of several criteria are met, including that “not all of the study’s pre-specified primary outcomes have been reported” or “one or more primary outcomes is reported using measurements, analysis methods or subsets of the data (e.g. subscales) that were not pre-specified”. In the PACE Trial, the third primary outcome measure (the number of "overall improvers") was never published. Also, the other two primary outcome measures were reported using analysis methods that were not pre-specified (including switching from the bimodal to the Likert scoring method for The Chalder Fatigue Scale, one of the primary outcomes in your review). These facts mean that the “high risk of bias” category should apply.

Thank you for taking the time to read my comments.

Tom Kindlon

Conflict of Interest statement:

I am a committee member of the Irish ME/CFS Association and do a variety of unpaid work for the Association.

(continues)

On 2015 Sep 14, Tom Kindlon commented:

Comment 1 of 2 formally submitted on September 9, 2015 using instructions here: http://www.cochranelibrary.com/help/submitting-comments-on-cochrane-reviews.html

(This is available in one piece at: http://forums.phoenixrising.me/index.php?threads/my-two-detailed-comments-on-the-cochrane-exercise-therapy-for-cfs-review-2015.39801/ )

I would first like to thank those involved for their work in preparing this document. Even for those of us who have read the individual Chronic Fatigue Syndrome (CFS) papers it is useful to have the results collated, as well as details regarding the interventions. Also it is interesting to see the results of sensitivity analyses, subgroup analyses, standardised mean differences, etc.

I would like to make a few comments. I’m splitting them into two submissions as the piece had become very long. I’ve added some loose headings to hopefully make it more readable.

Objective measures

The review assessed the studies as having a high risk of bias regarding blinding, since neither participants nor assessors were blinded. Evidence suggests that subjective outcomes are more prone to bias than objective outcomes when there is no blinding (1). It is thus unfortunate that the review concentrated almost exclusively on subjective measures, failing to include results from nearly all the objective outcome measures that have been published with trials. (The exception was health resource use for which you presented follow-up data from one trial).

I hope objective outcome data can be included in a future revision or edition of this review.

Examples of objective outcomes include: exercise testing (work capacity by oxygen consumption); fitness test/step test; the six minute walking test; employment status; and disability payments.

Adding in these results would allow a more rigorous assessment of the effectiveness and relevance of the therapies, their causal mechanisms, therapeutic compliance, and safety.

On exercise testing, for example, in the PACE Trial (the largest trial in the review) there was no improvement in fitness levels as measured by a step test (2). The fitness data contrasts sharply with the many positive results from subjective self-report measures in the trial, so one is left wondering how much the subjective measures reflect reality.

On another exercise test used in the PACE Trial, the 6 minute walk test, there was a small (mean) increase from 312 metres at baseline to 379 metres at 12 months: this was 35.3 metres more than the "passive" control group when adjustments were made. However, the final result of 379 metres remains very poor compared to the more than 600 metres one would expect from healthy people of a similar age and gender make-up (3,4). By comparison, a group with Class III heart failure walked an average of 402 metres (5). A score of less than 400 metres has been suggested as the level at which somebody should be put on a lung transplant list (6). Such information from objective measures helps to add important context to the subjective measures and restraint to the conclusions that can be drawn from them.

Objective data is also needed to check compliance with a therapy. If patients diligently exercised for 12 months one would expect much better results on fitness and exercise testing than the aforementioned results in the PACE Trial. This is important when considering adverse events and safety: such trials may not give us good information on the safety of complying with such interventions if patients haven't actually complied.

Employment and receipt of disability payments are practical objective measures of general functional capacity so data on them would help establish whether patients can actually do more overall or whether they may just be doing, for example, a little more exercise but have substituted that for doing less in other areas (7,8). Also, CFS patients are sometimes pressured by insurance companies into doing graded exercise therapy (GET) programs so it would be useful to have data collated on employment outcomes to see whether pressure can in any way be justified (9,10). In the PACE Trial, there was no significant improvement in employment measures and receipt of disability payments in the GET group (11). Outside the realm of clinical trials, the quantitative and qualitative data in a major (UK) ME Association survey also found that GET didn't lead to higher levels of employment and lower levels of receipt of disability payments on average (9). Also, extensive external audits were performed of Belgian CFS rehabilitation clinics that treated using cognitive behavioural therapy (CBT) and GET. The main reports are in French and Dutch (12,13), with an English summary available (14) that says, "Employment status decreased at the end of the therapy, from an average of 18.3% of a 38h working week, to 14.9% [...] The percentage of patients living from a sickness allowance increased slightly from 54 to 57%." This contrasts with the average improvements reported in the audit for some symptoms like fatigue.

While data on (self-reported) symptoms like fatigue (one of your two primary outcomes) is interesting, arguably more important to patients is improving their overall level of functioning (and again, objective measures are needed here). Being able to work, for example, despite experiencing a certain level of fatigue would likely be more important for many than being unable to work but having slightly lower levels of fatigue.

An example of how reductions in the reported levels of fatigue may not lead to improvements in functioning can be seen in an analysis of three graded activity-oriented CBT therapy interventions for CFS (15). The analysis showed, compared to controls, there were no improvements in overall activity levels as measured by actometers despite improvements in self-reported fatigue (15). Activity in these trials was assessed using actometers. Another study that exemplifies the problem of focusing too much on fatigue scores after behavioural interventions is a study of CBT in multiple sclerosis (MS) patients with “MS fatigue”(16). The study found that following the intervention, patients with MS reported significantly lower (i.e. better) scores on the Chalder Fatigue Scale (0-33 scoring) than those in a healthy, nonfatigued comparison group! This significant difference was maintained at 3 and 6 months’ follow-up. It is difficult to believe that patients with MS fatigue (at baseline) truly subsequently had less fatigue than healthy nonfatigued controls: a much more likely scenario is that undertaking the intervention had led to response biases.

You mention that "many patient charities are opposed to exercise therapy for chronic fatigue syndrome (CFS)". One reason for concern about the way in which exercise programmes are promoted to patients is that they are often based upon models which assume that there is no abnormal physiological response to exercise in the condition, and make unsupported claims to patients. For example, in the FINE trial (Wearden et al., 2010) patient booklet (17), it is boldly asserted that: "Activity or exercise cannot harm you" (p. 49). However, a large number of studies have found abnormal responses to exercise, and the possibility of harm being done simply cannot be excluded on the basis of current evidence (discussed in 4, 18-20)."

(continues)

On 2015 Feb 24, Laurie Thomas commented:

Clinical studies of chronic fatigue syndrome are plagued by serious problems in the inclusion/exclusion criteria. These problems stem from the fact that the syndrome consists of nonspecific symptoms that are "medically unexplained." However, there is a major difference between medically unexplained and medically inexplicable. The symptoms of chronic fatigue syndrome can result from a serious circulatory problem that is easily overlooked. In 2003, Peckerman and coworkers showed that low cardiac output, as measured by impedance cardiography, predicts the severity of symptoms in CFS patients.[1] Miwa and Fujita found a small left ventricular size leading to low cardiac output in CFS patients with orthostatic intolerance.[2] Porter and coworkers reported that a case of femoral arteriovenous fistula causing high-output cardiac failure was originally misdiagnosed as chronic fatigue syndrome.[3]

The studies of graded exercise for management of CFS are based on the presumption that CFS is the result of laziness and deconditioning and that the solution to the problem is to persuade the patient to exercise. Yet in many reported cases, the real problem was unrecognized cardiac decompensation. This state of cardiac decompensation could account for the push-crash phenomenon (serious, prolonged adverse events from overexertion) among people with CFS. Thus, a graded exercise program that might be beneficial for the large number of people who are tired and achy because of major depressive disorder could be catastrophic for the relatively small number of people whose problem is due to cardiac decompensation. Unfortunately, the existing studies of exercise for management of CFS do not shed light on this problem. The patients whose exercise intolerance is too severe to allow them to participate in the exercise program might refuse to enroll or might be dismissed as noncompliant if they try but fail to exercise. Yet as a result of the positive results of graded exercise for subjects whose real problem is major depressive disorder, patients with unrecognized cardiac decompensation are being scolded for failing to exercise.

For ethical and scientific reasons, the protocol for a clinical study of subjects with CFS should be based on the best possible model for clinical management of CFS patients. It would begin with a careful assessment of the subject's circulatory status. This assessment should include a tilt-table test, or at least a measurement of supine, sitting, and standing pulse and blood pressure. Any circulatory problem should be addressed appropriately. (Note that once the patient's condition is found to be due to a circulatory problem, the patient no longer fits the inclusion criteria of "medically unexplained" symptoms.)

As improper diet is the most prevalent cause of chronic ill-health, the cardiology assessment should be followed by a run-in period of at least a week of optimal dietary management. Subjects should be fed a low-fat (<10% of calories), purely plant-based diet that excludes the most common causes of food allergies or intolerance syndromes (i.e., wheat, rye, barley, corn, soy, strawberries, and citrus fruits). To ensure adherence, the diet should be administered in a residential setting. This kind of low-fat, plant-based diet can bring about a significant drop in blood pressure in hypertensive patients within 7 days, even if the patients stop taking blood pressure medication at baseline.[4] This correction of hypertension results from the decrease in systemic resistance. Thus, this diet could lead to a significant improvement in circulation, which would be beneficial to patients whose symptoms are due to poor circulation, even if they are not hypertensive. Note also that the elimination of poorly tolerated foods is the only reliable way to establish that the patient's problem is due to a food intolerance. Of course, once the subject's problem has been shown to be dietary in origin, the subject no longer has "medically unexplained" symptoms and thus no longer fits the inclusion criteria for a study of CFS.

Many patients with a diagnosis of CFS are inactive, but they may be inactive because they are sick, rather than being sick because they are inactive. Thus, any study of exercise and CFS should be structured to establish the direction of causality. If a study of subjects with a diagnosis of CFS involves exercise, the outcome variables must involve some measurement of the subjects' overall activity levels, not just to assess compliance with the exercise program but to assess whether the subjects are merely wasting their energy on the exercises and thus become less able to perform activities of daily living. In that situation, the exercise program could actually decrease the subject's quality of life.

[1] Peckerman A, LaManca JJ, Dahl KA, Chemitiganti R, Qureishi B, Natelson BH. Abnormal impedance cardiography predicts symptom severity in chronic fatigue syndrome. Am J Med Sci. 2003 Aug;326(2):55-60.

[2] Miwa K1, Fujita M. Small heart with low cardiac output for orthostatic intolerance in patients with chronic fatigue syndrome.Clin Cardiol. 2011 Dec;34(12):782-6. doi: 10.1002/clc.20962. Epub 2011 Nov 28.

[3] Porter J1, Al-Jarrah Q1, Richardson S. A case of femoral arteriovenous fistula causing high-output cardiac failure, originally misdiagnosed as chronic fatigue syndrome. Case Rep Vasc Med. 2014;2014:510429. doi: 10.1155/2014/510429. Epub 2014 May 20.

[4] McDougall J1, Thomas LE, McDougall C, Moloney G, Saul B, Finnell JS, Richardson K, Petersen KM.Effects of 7 days on an ad libitum low-fat vegan diet: the McDougall Program cohort. Nutr J. 2014 Oct 14;13:99. doi: 10.1186/1475-2891-13-99.

On 2015 Feb 19, Joan Crawford commented:

This review states: “Chronic fatigue syndrome (CFS) is characterised by persistent, medically unexplained fatigue, as well as symptoms such as musculoskeletal pain, sleep disturbance, headaches and impaired concentration and short-term memory.”

This is important because the above description of CFS and the addition of trials in the review only requiring chronic fatigue as an inclusionary requirement (Sharpe et al, 1991) makes generalisation of the findings problematic as many patients with major depressive disorder (MDD) would also meet the above description of CFS and Sharpe et al.'s (1991) criteria if their condition was fatiguing – a common feature - along with muscular aches and pains, sleep disturbance, cognitive difficulties and so on. The high percentage of patients included in these trials suffering from depression (Table 1. Study demographics) indicates this may be their primary condition – confounding the results. Exercise, through behavioural activation programs, has a moderately positive impact on patients with depression (Cooney et al., 2013). It is unclear whether the modest improvement seen in some of these trials can be accounted for by an improvement in low mood caused by depression. Moreover, where there is data there is a high usage of antidepressants in patients included in the reviewed trials (Table 1. Study demographics).

Of the eight exercise trials included in this review, five used broad inclusion criteria (Sharpe et al, 1991) (N=1287) – 85% of all participants. Two of these studies also used a version of the London criteria, which did not exclude patients with depression and other psychiatric conditions as originally specified by the authors making it hard to assess how these criteria were operationalised. Three further trials used the CDC Fukuda (1994) CFS criteria (N=231). While these purport to be more selective, they do not necessary include patients whose primary difficulties include post exertional weakness and debility and flu-like symptoms and so on beyond broadly defined fatigue and other general symptoms which could be attributed to CFS or MDD.

There is also an issue with lack of evidence of patients’ fidelity to exercise programs using objective measures. We do not know if patients increased their activity as suggested to them by their clinicians. Without using devises such as actimeters or pedometers to track daily activity levels we have no accurate way of assessing whether an increase in activity occurred and whether this helps. Black & McCully’s (2005) study demonstrates objectively the difficulties patients face when trying to increase activity and concluded that they were exercise intolerant, unable to sustain activity targets.

The report is bold in stating “no evidence suggests that exercise therapy may worsen outcomes“. Many patient surveys from across the world report numerous instances of harm and worsening of symptoms from taking part in exercise programs. For a summary of the difficulties and limitations of the reporting of harms, in and outside of clinical trials, and why these might be underestimated please see Kindlon (2011).

References

Cooney GM, Dwan K, Greig CA, Lawlor DA, Rimer J, Waugh FR, McMurdo M, Mead GE (2013). Exercise for depression. The Cochrane Library. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD004366.pub6/abstract

Fukuda, K., Straus, S.E., Hickie, I., Sharpe, M.C., Dobbins, J.G., & Komaroff, A. (1994). The chronic fatigue syndrome: A comprehensive approach to its definition and study. International chronic fatigue syndrome study group. Annals of Internal Medicine, 121(12), 953-959.

Kindlon T. (2011). Reporting of harms associated with graded exercise therapy and cognitive behavioural therapy in Myalgic Encephalomyelitis/chronic fatigue syndrome. Bulletin of the IACFS/ME. 19(2): 59-111.

M, Archard L, Banatvala J, Borysiewicz LK, Clare AW, David A, et al. (1991). Chronic fatigue syndrome: guidelines for research. Journal of the Royal Society of Medicine, 84(2):118–21.

On 2015 Feb 14, Ellen M Goudsmit commented:

I had contact with the main author to alert her to certain misconceptions published earlier. Sadly, I found I had wasted my time.

For example, we can not tell how many, if any, patients in the PACE trial met the London criteria. Having read that the researchers planned to select individuals with ME and had listed the criteria in the protocol, I checked that Prof. White would use the original version which had not been published. I had been the Chair of the Research Working Group at AFME when they were being tested and still had a copy. They came with a questionnaire as well as a physician to establish their reliability. Prof. White was unwilling to confirm that he would use the original so in light of the uncertainty, I requested that he did not cite me as a co-author. I did not work on the lay version published in the Westcare report which I felt was deeply flawed. I was right to be cautious. The trial manual indicates that the researchers adapted the lay version and I could tell from the results that the London criteria were not used as they exclude individuals with psychological disorders so the percentage for that variable should have been nil. It wasn’t.

A second point. The review does not pay the required attention to the lack of actigraphy, an objective measure to confirm fidelity to the protocol. This has been included in most studies conducted in the USA and the Netherlands. The results from actigraphy indicate that, except for 7 individuals, there were no significant increases in activity after GET and similar therapies. According to Friedberg who assessed the phenomenon, patients on exercise trials tend to reprioritise their activities, choosing those that result in less stress etc. In short, they learn to pace themselves (Goudsmit et al 2012). That is why they feel better and less fatigued, but it's not possible to attribute improvement to an increase in activity (or fitness).

Pacing was not defined and adaptive pacing therapy (APT) refers to a programme consisting of several components including stress management, advice on sleeping etc. There are no data for pacing alone in the PACE trial, so to conclude that GET is superior to pacing therapies is premature. There is only one pacing therapy. Pacing is not a therapy. It's a simple strategy. Research by Jason suggests that people who pace themselves feel better, irrespective of the protocol they are on.

Finally, we know that many patients have adverse reactions to activity. It's a criterion for diagnosis. To dismiss them ("no evidence that exercise therapy worsens outcomes") is hard to comprehend. Every survey in every country to date has revealed that GET does have marked adverse reactions and can result in relapse. See also Sisto et al and Black and McCully, cited in Goudsmit et al 2012.

To summarise: lack of a definition of pacing resulting in confusion, repetition of incorrect information, failure to consider the findings from objective measures suggesting patients did not adhere to the protocol and ignoring consistent reports from surveys that undermine one's conclusions. I expect more objectivity and attention to detail from the Cochrane Library.

Goudsmit, EM., Jason, LA, Nijs, J and Wallman, KE. Pacing as a strategy to improve energy management in myalgic encephalomyelitis/chronic fatigue syndrome: A consensus document. Disability and Rehabilitation, 2012, 34, 13, 1140-1147. Online 19th December. doi: 10.3109/09638288.2011.635746.

On 2015 Mar 12, Donald Forsdyke commented:

ADAPTATION DECOUPLED FROM SPECIATION. The authors begin by noting that gene flow among populations, rather than assisting speciation, has a “greater impact” when acting “as a homogenizing force, reuniting populations that might otherwise have had separate evolutionary trajectories.” This blending effect, which thwarts speciation, is prevented by some form of reproductive isolation dependent upon an internal or external barrier. The nature of the barrier varies with time. The present work reflects on the order in which barriers arise, an early barrier being superceded by a later.

The two fern types, having diverged 60 million years ago, can still transfer gametes abiotically (so there are no genic incompatibilities conferring prezygotic isolation), and the resulting zygotes can still develop (so there are no genic incompatibilities conferring hybrid inviability). Thus, they are reproductively isolated to a degree sufficient to prevent blending, solely by virtue of hybrid sterility.

Following a line of reasoning that dates back to Romanes (1886), a failure of meiotic pairing, due to the accumulation of base differences in parental DNA sequences (that would not necessarily affect genes), results in sterile hybrids. The line cannot advance, so that in evolutionary terms the parents are reproductively isolated from each other. Over 60 million years, this chromosome pairing barrier would have been elevated by addition of macroscopically observable deletions, duplications or inversions. Accompanying genic changes would have affected phenotypic functions other than those affecting fertilization and development. Thus secondary adaptations would be decoupled from the primary speciation event. This is in keeping with the recent conclusion of Hedges et al. (2015) that “if adaptation is largely decoupled from speciation, we should not expect it to be a driver of speciation” (see: http://1.usa.gov/1ESNM0W where further references may be found).

On 2015 Jun 10, Paul Golding commented:

Baggott and Tamura imply that my experiment was flawed because: “The study design by Golding (2014) should have included a balanced supplementation of micronutrients at the level of generally recommended dietary intakes.” and advise that “Therefore, the data presented by Golding (2014) must be cautiously interpreted”.

My full response is available here.

Was the 500 mg/day vitamin C supplement excessive, and could it have abnormally extended the time taken to deplete the liver folate store?

Baggott and Tamura claim that my 500 mg/day vitamin C supplement was excessive, and that my saturated vitamin C status was abnormal. They propose that by abnormally protecting the reduced (unstable) form of folate from oxidation, which they claim would not have been preserved by recommended vitamin C intakes, the “excessive” vitamin C preserved the liver folate store. I strongly disagree with these assertions.

Carr et al (2012), Levine et al. (1996) and Lykkesfeldt and Poulsen (2010) recommend that vitamin C intake should be sufficient to ensure plasma saturation. If the plasma vitamin C concentration is insufficient to prevent oxidation of fully reduced folate, although sufficient to prevent scurvy, there would be sub-optimal vitamin C status.

There is no evidence that, once there is sufficient vitamin C present to ensure plasma saturation, and thereby protect the fully reduced folates, additional amounts will affect the time taken to develop folate deficiency.

Levine et al. (1996) recommend 200 mg vitamin C daily, very significantly higher than the 70 mg taken by Herbert (Herbert 1962), and a level that ensures plasma saturation. They plotted plasma vitamin C concentration against the daily vitamin C dose (Levine et al. 1996 Figure 1C); this produced a sigmoid curve with 200 mg the lowest dose to reach a plateau.

I used data from Levine et al. (1996 Table 1) to produce a chart to illustrate the relationship between vitamin C dose and the plasma concentration, at relevant levels. At Herbert’s dose of 70 mg/day, plasma concentration is 32 µmol/L; at 200 mg/day recommended by Levine et al. (1996), plasma concentration is 66 µmol/L; at my dose of 500 mg/day, plasma concentration is 71 µmol/L. A 500 mg dose of vitamin C will not produce a significantly higher plasma concentration than the 200 mg dose recommended by Levine et al. (1996), but a 70 mg dose will produce a very significantly lower plasma concentration. The Excel file, high-resolution PDF and Microsoft PowerPoint slide for my chart are available at the link above.

The predicted plasma vitamin C concentration of 71 µmol/L, produced by my intake of 500 mg/day, is very close to the value considered by Carr et al. (2012) to be necessary for good health.

The vitamin C supplement used by me was integrated with the iron tablets taken to prevent the iron deficiency reported by Herbert. As stated in Golding (2014), the iron tablets (Abbott Australia Ferro-Grad C) comprised 325 mg ferrous sulphate (equivalent to 105 mg elemental iron), with 562 mg sodium ascorbate (equivalent to 500 mg vitamin C). Sodium ascorbate is necessary to ensure adequate absorption of the iron (Hurrell 2002, McCurdy 1968).

Was the 1000 µg/day vitamin B12 supplement excessive, and could it have abnormally extended the time taken for me to deplete my liver folate store?

Although Baggott and Tamura raise the possibility of such a confounding effect, they have not suggested any mechanism for it, or cited any published reports of such findings.

I found no published reports of vitamin B12 used to overcome a dietary folate deficiency, or any findings of interference by vitamin B12 supplements with folate metabolism where there was no initial vitamin B12 deficiency. An initially untreated vitamin B12 deficiency can cause a secondary functional folate deficiency; the “methylfolate trap” (Tisman and Herbert 1973). Such a secondary folate deficiency might be corrected by vitamin B12 supplements, depending on the cause of the vitamin B12 deficiency, but there is no published evidence that increasing the vitamin B12 intake beyond that will have any effect on folate metabolism.

As explained in Golding (2014), the 1000 µg/day vitamin B12 supplement was necessary to prevent vitamin B12 deficiency. Extensive testing during my previous vitamin B12 investigation showed that my vitamin B12 is absorbed and transported to cells normally but is not utilised adequately within the cells, presumably because of a deficiency of one of the B12 cofactors. At least 250 µg was needed to avoid deficiency but 1000 µg is the most readily available, allows a reasonable margin for error, and is within the recommended range for the oral vitamin B12 dose (Kuzminski et al. 1998).

Did the experiment include appropriate supplementation of micronutrients and was the title adequate?

Baggott and Tamura have not provided any evidence that taking either of these supplements could have interfered with the development of folate deficiency in my experiment, and have not offered any plausible mechanism for such confounding effects. In addition, my supplementation with vitamin C and vitamin B12 was reasonable, in the doses used, to prevent deficiencies.

I therefore disagree with their advice that “Therefore, the data presented by Golding (2014) must be cautiously interpreted”, and with what they imply in their conclusion; that my experiment was flawed because the study design failed to include “a balanced supplementation of micronutrients at the level of generally recommended dietary intakes.”

I also disagree with their assertion that “The title … should have contained words clearly indicating that the subject had a high initial folate status and was saturated with ascorbate.” My replete folate status was clearly stated in Objective, Experiment Design and The Subject. According to Levine et al. (1996), Carr et al. (2012) and Lykkesfeldt and Poulsen (2010), plasma saturation is the normal optimal vitamin C status.

References

Baggott JE, Tamura T (2014) The second study of experimental human folate deficiency. SpringerPlus 3:719

Carr AC, Pullar JM, Moran S, Vissers MC (2012) Bioavailability of vitamin C from kiwifruit in non-smoking males: determination of 'healthy' and 'optimal' intakes. J Nutr Sci 1:e14

Golding PH (2014) Severe experimental folate deficiency in a human subject – a longitudinal study of biochemical and haematological responses as megaloblastic anaemia develops. SpringerPlus 3:442

Herbert V (1962) Experimental nutritional folate deficiency in man. Trans Assoc Am Physicians 75:307–320

Herbert V (1987) Recommended dietary intakes (RDI) of folate in humans. Am J Clin Nutr 45(4):661–670

Hurrell RF (2002) Fortification: overcoming technical and practical barriers. J Nutr 132(4 Suppl):806S–812S

Kuzminski AM, Del Giacco EJ, Allen RH, Stabler SP, Lindenbaum J (1998) Effective treatment of cobalamin deficiency with oral cobalamin. Blood 92(4):1191-1198

Levine M, Conry-Cantilena C, Wang Y, Welch RW, Washko PW, Dhariwal KR, Park JB, Lazarev A, Graumlich JF, King J, Cantilena LR (1996) Vitamin C pharmacokinetics in healthy volunteers: evidence for a recommended dietary allowance. Proc Natl Acad Sci 93(8):3704–3709

Lykkesfeldt J, Poulsen HE (2010) Is vitamin C supplementation beneficial? Lessons learned from randomised controlled trials. Br J Nutr 103(9):1251-1259

McCurdy PR, Dern RJ (1968) Some therapeutic implications of ferrous sulfate-ascorbic acid mixtures. Am J Clin Nutr 21(4):284–288

Tisman G, Herbert V (1973) B12 dependence of cell uptake of serum folate: an explanation for high serum folate and cell folate depletion in B 12 deficiency. Blood 41(3):465–469

On 2015 Mar 10, Ben A Inglis commented:

The parameters for the magnetization preparation (MP) RF pulse are not given in the paper, the supplemental material nor in the authors' previous work (Franklin et al 2013, Franklin et al 2014) on blood flow effects in gray matter measured with MP-RAGE. Was a non-selective or slab-selective inversion pulse used? The latter is expected to have more flow weighting than the former. Also, what was the inversion time (TI)? The value of TI will also influence flow weighting. In this report as well as the two prior reports, the TR quoted is considerably shorter than the TR typically employed when using a TI of 700-900 ms at 3 T. Was the magnetization preparation actually enabled? Finally, given that the paper contends there is an effect of blood flow in assessing gray matter with MP-RAGE, discussion of the effects of the MP scheme on flow weighting is essential. As given the paper fails to explain the mechanism of the blood flow weighting and whether there might be ways to minimize effects, e.g. by using a non-selective inversion and particular inversion times.

On 2016 Jan 12, Tamás Ferenci commented:

I have replied to this paper criticizing certain aspects of it (Ferenci T, 2017), available for download here, to which the original authors also responded (Diamond DM, 2017), available for download here.

On 2015 Nov 01, John Tucker commented:

The authors correctly point out that the use of relative risk information in isolation can be misleading, but this is true of their preferred measure of absolute risk reduction as well. The examples chosen by the authors to illustrate their point are 2 to 5 year trials of drugs that are taken prophylactically for much longer periods. Further, two were stopped early for ethical reasons after crossing the threshold for showing clear clinical benefit, which placed an upper limit on the level of benefit that could be demonstrated. The survival curves from longer term trials such as 4S and WOSCOPS show a progressively larger absolute benefit with longer duration of treatment.

Presented in isolation, both relative and absolute risk reduction can be misleading.

On 2015 Feb 17, Ryan Radecki commented:

Post-publication commentary: "Inappropriately Promoted tPA "Drip and Ship" Safety"

“More community hospitals are giving a powerful clot-busting medication to stroke victims, improving their chances of survival and recovery, new research shows.”

This statement comes from coverage of the American Heart Association release regarding this synopsis of the Get-With-the-Guideline Registry. Part of this statement is true – more community hospitals are using tPA for acute ischemic stroke. In this review of 44,667 patients treated with tPA over the past decade, 23.5% received tPA outside of a specialized stroke or academic center.

The second half of this press statement is false.

Patients treated by the “drip and ship” method, as community administration of tPA is described, did not have an improved chance of survival. Patients treated at community hospitals were younger, had less-severe strokes, and had fewer prior strokes – yet their in-hospital mortality was 10.9%, compared with 9.7%....

http://www.emlitofnote.com/2015/02/inappropriately-promoted-tpa-drip-and.html

On 2015 Feb 17, Ryan Radecki commented:

Post-publication commentary: "Christmas Comes Early for Endovascular Therapy in Stroke"

Quite literally, in fact, considering the timing of the publication of MR-CLEAN – and, now, the triple fall-out from those results.

Due to the positive findings presented by the MR-CLEAN investigators in December 2014, three other ongoing major endovascular trials used this opportunity to check their results early. ESCAPE, EXTEND-IA, and SWIFT-PRIME – all products of the Covidien Solitaire FR clinical trial machine – ceased recruitment and looked to see if they’d met statistical measures of efficacy. Obviously, if you’re reading about all three of these trials here today – presented at the International Stroke Conference yesterday – they all found the results they hoped. ESCAPE and EXTEND-IA were published simultaneously in the NEJM, while SWIFT-PRIME is still in the manuscript drafting stages.

The more robust of the two trials is ESCAPE, whose original target enrollment was 500 patients based on a primary outcome of “ordinal shift analysis” on the modified Rankin scale.....

http://www.emlitofnote.com/2015/02/christmas-comes-early-for-endovascular.html

On 2015 Feb 17, Ryan Radecki commented:

Post-publication commentary: "Christmas Comes Early for Endovascular Therapy in Stroke"

Quite literally, in fact, considering the timing of the publication of MR-CLEAN – and, now, the triple fall-out from those results.

Due to the positive findings presented by the MR-CLEAN investigators in December 2014, three other ongoing major endovascular trials used this opportunity to check their results early. ESCAPE, EXTEND-IA, and SWIFT-PRIME – all products of the Covidien Solitaire FR clinical trial machine – ceased recruitment and looked to see if they’d met statistical measures of efficacy. Obviously, if you’re reading about all three of these trials here today – presented at the International Stroke Conference yesterday – they all found the results they hoped. ESCAPE and EXTEND-IA were published simultaneously in the NEJM, while SWIFT-PRIME is still in the manuscript drafting stages.

EXTEND-IA was a much smaller trial, targeting only 100 patients, with coprimary outcomes of reperfusion and NIHSS improvement at 24 hours....

http://www.emlitofnote.com/2015/02/christmas-comes-early-for-endovascular.html

On 2015 Apr 22, Melissa Raven commented:

Inappropriate analysis of mortality in mental disorders

There are serious problems with this analysis of mortality in mental disorders. Walker et al. have very inappropriately generalized mortality estimates derived from their analysis of clinical samples (primarily tertiary treatment samples), which include high proportions of patients (often inpatients) with psychotic disorders, to cases of common mental disorders (primarily anxiety disorders and mood disorders) identified in population surveys (World Mental Health (WMH) surveys). The authors have thereby grossly exaggerated the population-level mortality due to mental disorders. Unfortunately this has been accepted uncritically by the reviewers, the editors, and many readers.

I have posted a more detailed comment on JAMA Psychiatry http://archpsyc.jamanetwork.com/article.aspx?articleid=2110027

On 2015 Mar 10, Harri Hemila commented:

Vitamin C may help against exercise-induced bronchoconstriction

Boulet LP, 2015 reviewed the treatment options for exercise-induced bronchoconstriction (EIB) and stated that there is insufficient data to recommend vitamins or antioxidants as treatment. This statement is misleading.

Three randomized trials examined the effect of vitamin C on exercise-induced FEV1 decline in asthmatics, see Schachter EN, 1982, Cohen HA, 1997, and Tecklenburg SL, 2007. Each trial found that vitamin C halved the FEV1 decline, with the pooled estimate indicating a reduction of postexercise FEV1 decline by 48% (95%CI: 33% to 64%), see Hemilä H, 2013 and Hemila H, 2014. The studies were carried out in three different decades and on two different continents, and the mean ages of the participants were 14 yr in Cohen HA, 1997 and 25-26 yr in Schachter EN, 1982 and Tecklenburg SL, 2007. It is not evident how far the estimate of effect can be generalized, but similar findings from such dissimilar studies indicate that vitamin C may be effective for a wider population who suffer from EIB.

Boulet LP, 2015 refers to the Cochrane review by Wilkinson M, 2014 as a justification for the statement that there are insufficient data on vitamins or antioxidants as treatment of EIB. However, Wilkinson M, 2014 does not include any of the above mentioned three RCTs in their analyses, since their analysis is restricted to studies that used both vitamin C and vitamin E together. Those studies are not relevant to the question whether vitamin C alone has effects on EIB.

Given the safety and low cost of vitamin C and the consistency in the findings of the three RCTs on vitamin C and EIB, it would seem reasonable to encourage physically active people to test whether vitamin C is beneficial on an individual basis, if they suffer from EIB.