The effect of seat belts on minor and severe injuries measured on the abbreviated injury scale

Abstract

Following the implementation of seat belt wearing legislation in Victoria in December 1970, the Royal Australasian College of Surgeons established a survey to collect detailed injury and crash data from car accidents in that State. An analysis of the effect of seat belt wearing on severe injuries sustained by car occupants during the first two years of the survey was reported by Cameron and Nelson[1977]. Minor injuries were ignored in that analysis. Further work extended the file to cover 8537 occupants injured during the first three years of the survey and the injuries (including minor injuries) were coded on the Abbreviated Injury Scale. This paper examines the effect of seat belt wearing on both minor and severe injuries. Some comparisons of injury severity distributions in the Victorian data and in data collected by North American MDAI teams are also made. The paper concludes that the wearing of static three-point lap/sash belts by front outboard seat occupants of cars and car derivatives is associated with: (a) Reduced likelihood of severe-to-fatal injury to the head-face, thorax, lower torso and lower extremities when injured and not ejected in crashes in built-up areas and, for some body regions, in open road crashes, (b) Increased likelihood of minor injury to the thorax and lower torso when injured and not ejected in crashes in all locations and of minor injury to the neck (i.e. whiplash) when injured and not ejected in crashes in built-up areas. There are suggestions that the increased likelihoods of the minor injuries are not artefacts of the injury criterion for inclusion, nor of the reduced likelihood of severe injury to the trunk when seat belts are worn, but are due to the wearing of the seat belt.