Impact of a helmet law on two wheel motor vehicle crash mortality in a southern European urban area.

BACKGROUND In Spain, a federal road safety law went into effect in the fall of 1992 extending to urban areas the unrestricted use of safety helmets by all two wheel motor vehicle occupants. OBJECTIVES To assess the effect of the law in reducing fatal motorcycle crash injuries; to estimate the number of lives saved; and to determine changes in the distribution of severity and anatomical location of injuries. METHODS Pre-test/post-test design of all deaths of two wheel motor vehicle occupants from 1990-92 (pre-law period) and from 1993-95 (post-law period) detected by the Barcelona Forensic Institute and the city police department. Injuries were coded using the 1990 version of the abbreviated injury scale. Poisson regression methods were used to model trends in mortality ratios and to provide estimates of the number of lives saved. RESULTS Between 1993 and 1995, 35 lives of two wheel motor vehicle occupants were spared, representing a decrease of 25% in the observed motorcycle crash mortality in the post-law period when compared with what would be expected if no such law had gone into effect. The proportion of deaths with severe head injuries was also reduced from 76% to 67% in the post-law period. CONCLUSIONS This study offers the first evaluation of a helmet law using combined forensic and police data in a large south European urban area where there is widespread use of motorcycles. Our results confirm the effectiveness of the helmet law, as measured by the reduction in the number of deaths and mortality ratios after the law implementation. The findings reinforce the public health benefits of mandatory non-restricted motorcycle and moped helmet use, even in urban areas with lower traffic speeds.