Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

BACKGROUND: Meta-analysis of randomized controlled trials (RCTs) should provide reliable evidence about the effects of interventions. This may be less reliable when only small trials are available. METHODS: The sample size was determined for all surgical RCTs included in Cochrane Collaboration systematic reviews. The difficulty in interpreting meta-analysis of small trials is illustrated using two specific reviews. RESULTS: The typical sample size for surgical RCTs was small with a median of only 87 participants. Only 39.8 per cent had adequate prerandomization treatment allocation concealment. In both systematic reviews that were assessed in detail, statistically significant early results from meta-analysis of several small RCTs did not reliably predict the results of subsequent RCTs. CONCLUSION: Surgical RCTs tend to be small and underpowered. Meta-analysis of such trials does not necessarily produce reliable results.

Original publication

DOI

10.1002/bjs.6988

Type

Journal article

Journal

Br J Surg

Publication Date

04/2010

Volume

97

Pages

466 - 469

Keywords

Anesthesia, General, Anesthesia, Local, Endarterectomy, Carotid, Humans, Meta-Analysis as Topic, Randomized Controlled Trials as Topic, Surgical Procedures, Operative