Observational studies of helmet use by bicyclists in Sweden were conducted once a year (average n = 37,031/year) during the period 1988-2002 (paper 1). The general trend in observed helmet wearing in different categories of bicyclists was analyzed by linear regression, and the results were used to predict future trends in helmet wearing. Three studies (papers II-IV) were also performed to evaluate a non-compulsory local bicycle helmet "law" in Motala municipality during the study period 1995 to 1998 (papers lI-IV). This law was introduced in 1996 and applies specifically to school children (ages 6-12 years), although the intention is to increase helmet use among all bicyclists. Adoption of the law was accompanied by helmet promotion activities. In one of the studies in the evaluation, written material and in-depth interviews (n=8) were analyzed qualitatively to describe the process and structure of development of the Motala helmet law. The other two studies used a quasi-experimental design to assess the impact of the helmet law: one comprised annual observations of helmet wearing among bicyclists in Morale (average n=2,458/year) and control areas (average n=17,818/year); and the other included questionnaire data on attitudes, beliefs, and self-reported behavior of school children in Motala (n=1,277) and control areas (n=2,198). The average response rate was 72.8 per cent. There was a significant upward trend in helmet use in all categories of bicyclists from 1988 to 2002. Helmet wearing increased from 20 per cent to 35 per cent among children (less than 10 years) riding bikes in their leisure time, from 5 per cent to 33 per cent among school children, and from 2 per cent to 14 per cent in adults. Total average helmet use rose from 4 per cent to 17 per cent. However, during the last five years of the study period (1998-2002), there was no upward trend in helmet wearing for any of the categories of bicyclists. If the historic trend in helmet use continues, the average wearing rate will be about 30 per cent by the year 2010. The Motala helmet law faced several problems, mainly during the initiation phase, and some of them led to poor promotion of the law in the schools and indistinct roles and responsibilities of the municipal actors. Despite that, the law initially led to a significant increase in helmet wearing among the primary target group (school children), from a pre-law level of 65 per cent to about 76 per cent six months post-law, whereas thereafter the wearing rate gradually decreased and was at the pre-law level 2 per cent years after the law was adopted. Nonetheless, a weak but significant effect on adult bicyclists remained: the pre-law level of about 2 per cent rose to about 8 per cent at the end of the study period. Only about 10 per cent of bicyclists on bike paths in Motala wore helmets two years post-law. The questionnaire study showed one significant effect on school children in Motala two years post-law, namely, a stronger intention to ride bicycles if a national compulsory helmet law was introduced. There was, however, no significant long-term influence on children's attitudes or beliefs about helmet wearing, which agrees with the results of the observational study.
Abstract