Teschke et al. BMC Public Health 2012, 12:765 http://www.biomedcentral.com/1471-2458/12/765 questioning may have produced reasonable results for al- cohol use as well. We did not collect data on the reasons why safety equipment was used or not, but we were able to examine an extensive list of personal and trip charac- teristics associated with equipment use. Finally, we did not collect information about many other types of individual-based equipment that may prevent injuries to cyclists, including reflective tape, reflectors, rear-view mirrors, disc versus rim brakes, and bells. Conclusions In this study of injured cyclists in two of Canada’s largest cities, we examined three types of individual-based safety equipment and found that helmets were the most fre- quently used, and were the only type of equipment used on the majority of trips. Helmets are a post-crash injury mitigation measure, whereas visibility aids are meant to allow other route users to detect and avoid a cyclist and thus prevent crashes from occurring. Studies of the in- jury reduction effectiveness of these pre-crash primary prevention devices are promising but rare, so this is an area worthy of further study. In the meantime, there is room for increasing awareness among cyclists and cyc- ling stakeholders of the enhanced detection provided by visibility aids and their potential to reduce collision risk. There were groups in the cycling population who were less likely to use each type of safety equipment, suggest- ing areas of focus for change. People who tended not to use bike lights or conspicuous clothing were those who cycle less and may have less knowledge about cycling equipment (e.g., weekend cyclists, less frequent cyclists). This suggests the potential value of communication campaigns like the ones that have increased helmet use. Another approach could include changes to bicycle sales, so that all commuter bikes are sold with lights (as motor vehicles are). The population not wearing helmets is smaller and may be more difficult to reach with add- itional messaging: those associated with risk-taking be- haviour (youth, men, people who have consumed alcohol); and those with less income and education. Strategies to prevent injuries in such populations may require a different focus: safety improvements in the cycling environment (e.g., lower motor vehicle speed limits on residential streets, dedicated bicycle infrastruc- ture including cycle tracks, bike lanes and paths) [8,26,33]. Such population-level approaches to injury prevention benefit all cyclists and may benefit other road users as well. Competing interests CCOR, MW, and PAC have held consultancies to related to their transportation or injury biomechanics expertise. PAC has stock in a company developing a helmet that he co-invented. All other authors have no financial or other relationships or activities that could appear to have influenced the submitted work. Page 8 of 9 Authors’ contributions KT, MAH, CCOR, and PC were responsible for initial conception and design of the study. KT, MAH, CCOR, PC, MW, MC, MDC, JB, GH, SB and SMF were responsible for the funding proposal. MAH, CCOR, MW, MM, MDC and KT designed and tested data collection instruments. JB, GH, SMF, and MDC contributed to identification of injured cyclists at the study hospitals. HS was responsible for data analyses. KT drafted the article. All authors contributed to study design and implementation, analysis decisions, interpretation of results, and critical revision of the article. Acknowledgements We thank the study participants for generously giving their time. We appreciate the many contributions of study staff (Lee Vernich, Evan Beaupré, Niki Blakely, Jill Dalton, Vartouji Jazmaji, Martin Kang, Kevin McCurley, Andrew Thomas), hospital personnel (Barb Boychuk, Jan Buchanan, Doug Chisholm, Nada Elfeki, Kishore Mulpuri), city personnel (Peter Stary, David Tomlinson, Barbara Wentworth) and community collaborators (Jack Becker, Bonnie Fenton, David Hay, Fred Sztabinski). The study was funded by the Heart and Stroke Foundation of Canada and the Canadian Institutes of Health Research (Institute of Musculoskeletal Health and Arthritis, and Institute of Nutrition, Metabolism and Diabetes). JRB, MAH, and MW were supported by awards from the Michael Smith Foundation for Health Research. MAH, CCOR, and MW were supported by awards from the Canadian Institutes of Health Research. Author details 1School of Population and Public Health, 2206 East Mall, University of British Columbia, Vancouver, BC, Canada. 2Department of Emergency Medicine, University of British Columbia, Vancouver, BC, Canada. 3Emergency Medicine, University Health Network, Toronto, ON, Canada. 4Department of Mechanical Engineering, ICORD and the Brain Research Centre, University of British Columbia, Vancouver, BC, Canada. 5Occupational Cancer Research Centre, Toronto, ON, Canada. 6Liu Institute for Global Issues, University of British Columbia, Vancouver, BC, Canada. 7School of Public Health, University of Toronto, Toronto, ON, Canada. 8Toronto Centre for Active Transportation, Toronto, ON, Canada. 9British Columbia Injury Research and Prevention Unit, Vancouver, BC, Canada. 10Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada. Received: 6 June 2012 Accepted: 3 September 2012 Published: 11 September 2012 References 1. Ogilvie D, Egan M, Hamilton V, Petticrew M: Promoting walking and cycling as an alternative to using cars: Systematic review. BMJ 2004, 329:763. 2. Noland RB: Perceived risk and modal choice: Risk compensation in transportation systems. Accid Anal Prev 1995, 27:503–521. 3. Winters M, Davidson G, Kao D, Teschke K: Motivators and deterrents of bicycling: comparing influences on decisions to ride. Transportation 2011, 38:153–168. 4. Beck LF, Dellinger AM, O'Neil ME: Motor vehicle crash injury rates by mode of travel, United States: using exposure-based methods to quantify differences. Am J Epidemiol 2007, 166:212–218. 5. Transport Canada: Canadian Motor Vehicle Traffic Collision Statistics; 2009. 2011, TP 3322 http://www.tc.gc.ca/eng/roadsafety/tp-tp3322-2009-1173.htm. 6. Agran PF, Castillo DN, Winn DG: Limitations of data compiled from police reports on pediatric pedestrian and bicycle motor vehicle events. Accid Anal Prev 1990, 22:361–370. 7. Haddon W: On the escape of tigers: an ecologic note. Am J Public Health 1970, 60:2229–2234. 8. Pucher J, Buehler R: Making cycling irresistible: Lessons from the Netherlands, Denmark and Germany. Transp Rev 2008, 28:495–528. 9. Reynolds CCO, Harris MA, Teschke K, Cripton PA, Winters M: The impact of transportation infrastructure on bicycling injuries and crashes: A review of the literature. Environ Health 2009, 8:47. 10. Crocker P, Zad O, Milling T, Lawson KA: Alcohol, bicycling, and head and brain injury: a study of impaired cyclists' riding patterns. Am J Emerg Med 2010, 28:68–72. 11. Li G, Baker SP, Smialek JE, Soderstrom CA: Use of alcohol as a risk factor for bicycling injury. JAMA 2001, 285:893–896.