Flipped out of control: single-vehicle rollover accidents in the Northern Territory.

OBJECTIVES To study the incidence of and factors associated with single-vehicle rollover (SVRO) accidents in the "Top End" of the Northern Territory (NT); to identify factors associated with major injury and death from SVRO accidents. DESIGN Retrospective analysis of records from the NT Department of Transport and Works' police database, Royal Darwin Hospital's trauma database, coroner's records, and case notes from public hospitals in the Top End. STUDY POPULATION All patients involved in SVRO accidents in the Top End between 1 January 1996 and 31 December 1997 whose accident was documented by the police, who attended a public hospital, or who died. MAIN OUTCOME MEASURES Types and incidence of all accidents; details of the accident scene, vehicle features, and population groups associated with SVRO accidents; factors associated with major injury and death. RESULTS SVROs accounted for 30% of all accidents and 29% of all injuries and deaths (441 people) in the whole of the NT over the study period. Some of the factors associated significantly more frequently with SVRO accidents were (i) occurrence of the accident on a straight, dry, unsealed road; (ii) presence of a vehicle defect; (iii) travelling at excessive speed; and (iv) the person being male, aged 41-50 years, of Aboriginal descent. Among the 147 people who were admitted to hospital or died from SVRO accidents in the Top End, major injury occurred significantly more frequently if the person was under the influence of alcohol, was not wearing a seatbelt and was ejected; if the accident occurred in a rural area; and if the vehicle was speeding. Major injuries occurred in 21% (31/147), and death was more likely in those with head, chest and neck injuries. CONCLUSION SVRO accidents are a major cause of morbidity and mortality in the Top End of the NT. Effective methods of limiting speeding, drink-driving and driver fatigue should be sought. Populations most at risk should be targeted.