title: The Bicyclists' Injuries and the Cycling Environment study: a protocol to tackle methodological issues facing studies of bicycling safety.
abstract: OBJECTIVE
  Bicycling may be less appealing in parts of the world where cycling is less safe. Differences between jurisdictions suggest route design is key to improving safety and increasing ridership. Previous studies faced difficulties in effectively assessing denominators for risk calculations and controlling confounding. This paper describes the advantages of the case-crossover design of the Bicyclists' Injuries and the Cycling Environment study to address these challenges to observational studies of cycling safety.
  
  
  METHODS
  Injured cyclists were recruited from the emergency departments of five hospitals in Vancouver and Toronto, Canada. In 18 months, 690 participants were successfully recruited and interviewed. Each participant was interviewed to map the route of their injury trip, identify the injury site and select two control sites at random from the same route. Infrastructural characteristics at each study site were scored by site observers who were blinded as to whether sites were crash or comparison sites. Analyses will compare infrastructural variables between case and control sites with conditional logistic regression.
  
  
  CONCLUSIONS
  This study presents a novel application of the case-crossover design to the evaluation of relationships between infrastructure and cycling safety while controlling confounders and exposure to risk. It is hoped that the value of this method and the efficiency of the recruitment process will encourage replication in other locations, to expand the range of cycling infrastructure compared and to facilitate evidence-based cycling infrastructure choices that can make cycling safer and more appealing.
authors.affiliation: Occupational Cancer Research Centre, Cancer Care Ontario, 505 University Avenue, Toronto, Ontario, Canada. harris.m.anne@gmail.com
authors.forename: M Anne
authors.initials: MA
authors.lastname: Harris
authors.forename: Conor C O
authors.initials: CC
authors.lastname: Reynolds
authors.forename: Meghan
authors.initials: M
authors.lastname: Winters
authors.forename: Mary
authors.initials: M
authors.lastname: Chipman
authors.forename: Peter A
authors.initials: PA
authors.lastname: Cripton
authors.forename: Michael D
authors.initials: MD
authors.lastname: Cusimano
authors.forename: Kay
authors.initials: K
authors.lastname: Teschke
mesh_terms: D001642:Bicycling / Q000293:injuries*; D002170:Canada; D015340:Epidemiologic Research Design; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods*; D012449:Safety