Journal Club Summary
Methodology Score: 3.5/5
Usefulness Score: 3.5/5
Quant EC, Jeste SS, Muni RH, Cape AV, Bhussar MK, Peleg AY.
BMJ. 2009 Sep 7;339:b3354. doi: 10.1136/bmj.b3354.
This meta-analysis of randomized controlled trials comparing the use of steroids alone vs steroids and antivirals in the treatment of Bell’s palsy found that there was no benefit to the use of antivirals, with an odds ratio for combined treatment of 1.50 (95% CI 0.83-2.69). JC attendees found the study very methodologically sound save for the abstraction error that led to significant alteration in final results (corrected OR with per protocol data of 1.72 (95% CI 1.02 – 2.88)). Taking the current literature into account attendees felt that this supports the idea that not all patients may benefit from antivirals but they should likely be offered to severely affected patients or very early presentations.
By: Dr. Valerie Charbonneau
Epi Lesson
Publication Bias in Systematic Reviews
Even when individual studies included in best evidence summaries have a low risk of bias, publication bias can result in substantial overestimates of effect. Authors should suspect publication bias when available evidence comes from a number of small studies, most of which have been commercially funded. A number of approaches based on examination of the pattern of data are available to help assess publication bias. The most popular of these is the funnel plot; all, however, have substantial limitations. The likelihood of publication bias is less for studies that are not evaluating new drugs or devices.
Even when individual studies included in best evidence summaries have a low risk of bias, publication bias can result in substantial overestimates of effect. Authors should suspect publication bias when available evidence comes from a number of small studies, most of which have been commercially funded. A number of approaches based on examination of the pattern of data are available to help assess publication bias. The most popular of these is the funnel plot; all, however, have substantial limitations. The likelihood of publication bias is less for studies that are not evaluating new drugs or devices.
By: Dr. Ian Stiell
