Study objectives: To determine the incidence of drugs of abuse and alcohol use in admitted drivers involved in motor vehicle crashes (MVCs) and to determine the rate of police detection of alcohol and drug use in these motorists.
Design: Retrospective chart review of hospitalized drivers involved in MVCs and review of corresponding police reports.
Setting: Two Level I trauma centers in a large metropolitan region.
Participants: All MVC drivers/motorcycle operators admitted to the trauma service from January 1, 1990, to December 31, 1990.
Measurements and main results: The records of 634 injured motorists were reviewed; 200 (32% of the 625 patients with serum alcohol levels) were legally drunk (serum alcohol of 100 mg/dL or more), and 132 (22.6% of the 585 urine drug screens) had positive urine drug screens. Cocaine was the most prevalent drug of abuse, present in 51 patients (8.7%). Two hundred eighty-five patients (45.0%) were considered impaired (alcohol of 100 mg/dL or more and/or positive drug screen), representing almost half of all motorists admitted. The impaired motorists were younger, more often male, less likely to use a seat belt or helmet, and had higher Injury Severity Scores than their unimpaired counterparts. Police reports were available for 446 patients, 139 (31.2%) of whom were legally drunk and 67 (15%) of whom had positive drug screens, yielding an overall impairment rate of 46.2%. Only 34 (16.5%) patients were cited for driving under the influence.
Conclusion: An exceedingly high rate of impairment existed in this population of seriously injured motorists in a metropolitan region, the majority of whom were not charged by the police. Although alcohol is the most prevalent source of driver impairment, other drugs of abuse are also important contributors to this problem.