On 2015 Jan 29, CREBP Journal Club commented:

This is a very informative and interesting paper, which highlights the utilities and caveats in the use of multiple-indication reviews. The coherent methodology of this article is admirable and we acknowledge that there is a lack of coherent terminology. The term “multiple-indication review” is unambiguous and should be used in future studies. We agree that producers of systematic reviews should consider using this kind of reviews instead of, or in addition to, reviews focusing on a single indication. Important information that we cannot get with traditional methods (single-indication reviews) can be achieved if this methodology is followed. For example, multiple-indication reviews are very useful in the fight against antibiotic resistance. Providing Health Care Professionals and patients with comprehensive information about the risk of adverse effects and the benefit-harm trade-off may reduce their desire for use of antibiotics. Chen et al identified three uses of multiple-indication reviews. However, we propose that the use of this kind of review can be broadly categorised as either:

● To get a better estimate of the effectiveness or harms e.g., 'What are the adverse effects of amoxicillin?' (P* I C H1, H2, …)

● To examine heterogeneity across indications or interventions e.g., 'When are prophylactic antibiotics effective?' (P1, P2, P3, … I C O1), or 'What is the optimum timing of prophylactic antibiotics before any surgery?' (P* I1 I2 I3, … C O1)

(PICO notation: P* = any disease; P1 P2 P3 = set of disease, I1 I2 I3 = set of interventions, C = comparison, O1 = outcome, H = harm)

When undertaking a multiple-indication review much attention has to be paid to the methodologically caveats such as ‘overlapping’ of included reviews; the extra level of complexity (potential heterogeneity in the contributing systematic reviews, in addition to heterogeneity in the primary trials); potential confounders (e.g. methodological quality of included studies and reviews) and risk of bias (e.g. different duration or dose of tested treatment or different control groups). Some of these methodological challenges can be dealt with in the designing of the review and some should be taken into account in the analytical approach. ‘Overlapping’ can be circumvented if only the data from the originals trials are included in the multiple-indication review. However, if the multiple-indication review is based on results from systematic reviews one need to take account of the potential ‘overlapping’ of included studies and we would be very interested in software routines to conduct these reviews - especially in a 2-step frequentist approach. See CREBP Journal Club for more information

On 2015 Jan 29, CREBP Journal Club commented:

This is a very informative and interesting paper, which highlights the utilities and caveats in the use of multiple-indication reviews. The coherent methodology of this article is admirable and we acknowledge that there is a lack of coherent terminology. The term “multiple-indication review” is unambiguous and should be used in future studies. We agree that producers of systematic reviews should consider using this kind of reviews instead of, or in addition to, reviews focusing on a single indication. Important information that we cannot get with traditional methods (single-indication reviews) can be achieved if this methodology is followed. For example, multiple-indication reviews are very useful in the fight against antibiotic resistance. Providing Health Care Professionals and patients with comprehensive information about the risk of adverse effects and the benefit-harm trade-off may reduce their desire for use of antibiotics. Chen et al identified three uses of multiple-indication reviews. However, we propose that the use of this kind of review can be broadly categorised as either:

● To get a better estimate of the effectiveness or harms e.g., 'What are the adverse effects of amoxicillin?' (P* I C H1, H2, …)

● To examine heterogeneity across indications or interventions e.g., 'When are prophylactic antibiotics effective?' (P1, P2, P3, … I C O1), or 'What is the optimum timing of prophylactic antibiotics before any surgery?' (P* I1 I2 I3, … C O1)

(PICO notation: P* = any disease; P1 P2 P3 = set of disease, I1 I2 I3 = set of interventions, C = comparison, O1 = outcome, H = harm)

When undertaking a multiple-indication review much attention has to be paid to the methodologically caveats such as ‘overlapping’ of included reviews; the extra level of complexity (potential heterogeneity in the contributing systematic reviews, in addition to heterogeneity in the primary trials); potential confounders (e.g. methodological quality of included studies and reviews) and risk of bias (e.g. different duration or dose of tested treatment or different control groups). Some of these methodological challenges can be dealt with in the designing of the review and some should be taken into account in the analytical approach. ‘Overlapping’ can be circumvented if only the data from the originals trials are included in the multiple-indication review. However, if the multiple-indication review is based on results from systematic reviews one need to take account of the potential ‘overlapping’ of included studies and we would be very interested in software routines to conduct these reviews - especially in a 2-step frequentist approach. See CREBP Journal Club for more information