On 2015 Dec 05, David Keller commented:
Patient-oriented result: response rate to magnetic stimulation was the same as to placebo
This study of repetitive transcranial magnetic stimulation (rTMS) was designed to test the hypothesis that rTMS would result in a "statistically significantly greater percentage of responders to treatment in an active rTMS group compared with a placebo rTMS group" [1]. A relatively new metric called the Tinnitus Functional Index (TFI) was used to measure response to treatment. The TFI rated 18 of the 32 subjects actively treated with rTMS as responders to treatment (56%), while only 7 of the 32 subjects treated with sham therapy were rated as responders (22%). These two rates differed significantly, which was pre-specified in the Objectives section as defining a successful outcome.
However, 7 of the 18 treated subjects rated as "responders to therapy" using the TFI scale nevertheless believed they had received sham therapy, implying that they did not perceive any treatment benefit beyond the placebo effect. When a subject states that his treatments seemed like sham therapy, providing only placebo-strength benefit, this is important information. Since it is a direct expression of the subject's assessment of the efficacy of rTMS therapy, it has more validity than a contrived metric like the TFI, from a patient-oriented perspective.
The data in e-Table 12 indicate that, of the 32 subjects who received active rTMS treatments, only 11 correctly guessed they had received active therapy at the end of the last treatment, which implies that only 11 out of 32 actively-treated subjects (about 34%) noted perceptible improvement in their tinnitus symptoms. Coincidentally, 11 of the 32 placebo-treated subjects (also 34%) guessed that they had received active rTMS therapy, which equals the placebo effect. Thus, active rTMS treatments had the same response rate as sham therapy, equal to the placebo effect of 34%.
Conclusion: rTMS is no more effective than placebo for treating tinnitus, when assessed by subjects after a full course of treatments, based on their perception of whether they received active or sham therapy. The advantage of this assessment is that it eliminates uncertainty about the accuracy and clinical relevance of the TFI metric, because the assessment of treatment benefit came directly from the subjects themselves.
Reference
1: Folmer RL, Theodoroff SM, Casiana L, Shi Y, Griest S, Vachhani J. Repetitive Transcranial Magnetic Stimulation Treatment for Chronic Tinnitus: A Randomized Clinical Trial. JAMA Otolaryngol Head Neck Surg. 2015 Aug;141(8):716-22. doi: 10.1001/jamaoto.2015.1219. PubMed PMID: 26181507.
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