Utvärdering av den svenska cykelhjälmslagen för barn under 15 år
Analys av nationella trender i cykelrelaterade huvudskador mellan 1998-2011
BicycleCyclistBicyclistHead injuryBicycle helmet legislationInjury trendsPopulation-based studyEpidemiologyInjury preventionInterventionEvaluationRiskCykelCyklistHuvudskadaCykelhjälmslagstiftningSkadetrenderPopulationsbaserad studieEpidemiologiSkadepreventionInterventionUtvärderingRisk
Introduction: In January 2005, a nationwide mandatory bicycle helmet law for children under the age of 15 was introduced in Sweden. In the current study, the effect of this law was evaluated by analyzing national trends in hospital admissions due to bicycle-related head injuries during the period 1998-2011.Methods: An interrupted time-series design with segmented regression analysis was used to evaluate the intervention effect on head injuries as a percentage of all injuries (%HI) among cyclists in age- and sex-specific groups. Effect was measured as a change in level and/or slope of the trend at the time of legislation.Results: A total of 35261 cyclists (0-54 years) were hospitalized due to a bicycle injury during the study period. Linear regression analyses of the entire study period (not segmented) showed significant year-to-year decreases in the %HI of 1.3-1.7% in all age and sex-specific groups (p < .0001). Results from the segmented regression analysis showed that, at the time of legislation, a significant drop in level occurred among males under 15 years (-4.5% [95% CI: -7.7% to -1.3%], p = .01) and a significant change in slope occurred among females aged 30-54 years (-1.6% [95% CI: -2.9% to -0.2%], p = .025).Conclusions: The law seems to have had an effect on males in the target population (<15 years). Although no significant changes were observed among females in this group as an immediate result of the law, the difference in %HI between genders was minimal at the end of the study period due to the steeper general decline among females.