Research highlights ► A meta-analysis of the effects of bicycle helmets published in Accident Analysis and Prevention in 2001 has been re-analysed. ► The re-analysis found that the original meta-analysis was influenced by publication bias and time trend bias it did not control for. ► When these sources of bias are controlled for, and new studies added to the analysis, the effects attributed to bicycle helmets become considerably smaller than originally reported. ► The findings of this meta-analysis are not consistent with a recently published Cochrane review.
Abstract This paper shows that the meta-analysis of bicycle helmet efficacy reported by Attewell, Glase, and McFadden (Accident Analysis and Prevention 2001, 345–352) was influenced by publication bias and time-trend bias that was not controlled for. As a result, the analysis reported inflated estimates of the effects of bicycle helmets. This paper presents a re-analysis of the study. The re-analysis included: (1) detecting and adjusting for publication bias by means of the trim-and-fill method; (2) ensuring the inclusion of all published studies by means of continuity corrections of estimates of effect rely on zero counts; (3) detecting and trying to account for a time-trend bias in estimates of the effects of bicycle helmets; (4) updating the study by including recently published studies evaluating the effects of bicycle helmets. The re-analysis shows smaller safety benefits associated with the use of bicycle helmets than the original study.
Publication bias and time-trend bias in meta-analysis of bicycle helmet efficacy: A re-analysis of Attewell, Glase and McFadden, 2001
Accident Analysis and Prevention ; 43 , 3 ; 1245-1251
2011-01-11
7 pages
Article (Journal)
Electronic Resource
English
Bicycle helmet efficacy: a meta-analysis
Online Contents | 2001
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