Effecgt of legislation on the use of bicycle helmets

Background: About 50 Canadian children and adolescents die each year from bicycle-related injuries, and 75% of all bicycle-related deaths are due to head injuries. Although the use of helmets can reduce the risk of head injury by 85%, the rate of voluntary helmet use continues to be low in many North American jurisdictions. We measured compliance before, during and after 1997, when legislation making the use of helmets mandatory for cyclists was enacted in Nova Scotia. Methods: In the summers and autumns of 1995 through 1999, trained observers who had a direct view of oncoming bicycle traffic recorded helmet use, sex and age group of cyclists in Halifax on arterial, residential and recreational roads. Sampling was done during peak traffic times of sunny days. We abstracted data from the Canadian Hospitals Injury Reporting and Prevention Program database on bicycle-related injuries treated during the same period at the Emergency Department of the IWK Health Centre, Halifax. Results: The rate of helmet use rose dramatically after legislation was enacted, from 36% in 1995 and 38% in 1996, to 75% in 1997, 86% in 1998 and 84% in 1999. The proportion of injured cyclists with head injuries in 1998/99 was half that in 1995/96 (7/443 [1.6%] v. 15/416 [3.6%]) (P = 0.06). Police carried out regular education and enforcement. There were no helmet-promoting mass media education campaigns after 1997. Interpretation: Rates of helmet use rose rapidly following the introduction of legislation mandating the use of helmets while bicycling. The increased rates were sustained for 2 years afterward, with regular education and enforcement by police.