Publication bias and time-trend bias in meta-analysis of bicycle helmet efficacy: A re-analysis of Attewell, Glase and McFadden, 2001 (vol 43, pg 1245, 2011)

This paper is a corrigendum to the previously published paper: Publication bias and time-trend bias in meta-analysis of bicycle helmet efficacy: A re-analysis of Attewell, Glase and McFadden, 2001 [Accid. Anal. Prev. (2011) 1245-1251]. This corrigendum was prepared to correct errors in data and analysis in the previously published paper. Like the previously published paper, this paper confirms 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) Ensuring the inclusion of all published studies by means of continuity corrections of estimates of effect relying on zero counts; (2) detecting and adjusting for publication bias by means of the trim-and-fill method; (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. (C) 2013 Elsevier Ltd. All rights reserved.