title: Misconceptions regarding case-control studies of bicycle helmets and head injury.
abstract: A number of published case-control studies have reported that bicycle helmets are associated with a reduced risk of head injury and brain injury among bicyclists who crashed. A paper in this journal offered several criticisms of these studies and of a systematic review of these studies. Many of those criticisms stem from misconceptions about the studies that have been done and about case-control studies in general. In this manuscript we review case-control study design, particularly as it applies to bicycle helmet studies, and review some aspects of the analysis of case-control data.
authors.affiliation: Harborview Injury Prevention and Research Center, University of Washington, Seattle, USA. peterc@u.washington.edu
authors.forename: Peter
authors.initials: P
authors.lastname: Cummings
authors.forename: Frederick P
authors.initials: FP
authors.lastname: Rivara
authors.forename: Diane C
authors.initials: DC
authors.lastname: Thompson
authors.forename: Robert S
authors.initials: RS
authors.lastname: Thompson
mesh_terms: D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D001642:Bicycling / Q000293:injuries*; D001930:Brain Injuries / Q000517:prevention & control; D016022:Case-Control Studies; D015986:Confounding Factors, Epidemiologic; D006259:Craniocerebral Trauma / Q000517:prevention & control*; D006260:Head Protective Devices; D006801:Humans; D016017:Odds Ratio