Geographic analysis of traffic injury in Wisconsin: impact on case fatality of distance to level I/II trauma care.

PURPOSE Traffic injuries are an important public health problem in Wisconsin. This paper examines geographic variations in the incidence and case fatality of traffic injuries, and evaluates proximity to Level I/II trauma care as a predictor of case fatality. METHODS Data on all persons injured in motor vehicle crashes on Wisconsin roadways during a 10-year period (1992-2001) were obtained from the Wisconsin Crash Outcome Data Evaluation System. Injury rates per 100 million vehicle miles traveled (VMT) and case fatality were visually displayed by county. Multiple logistic regression models were used to evaluate distance between crash site and Level I/II trauma care as a risk factor for fatality, controlling for other factors. RESULTS During the 10-year period, 50,300 people were severely injured in motor vehicle crashes and 7450 (15%) died. Injury rates per VMT were highest in the southeast counties. In contrast, case-fatality for all injuries and for severe injuries was highest in northern and western counties and significantly associated with distance from Level I/II trauma care after controlling for other predictors of case fatality. CONCLUSIONS Strategies are needed to reduce the disparity in traffic injury case fatality across the state and to improve outcomes for persons injured in counties distant from Level I/II trauma care.