Positive blood alcohol concentration and road accidents. A prospective study in an Italian emergency department.

STUDY OBJECTIVE To examine if a positive blood alcohol concentration (BAC) at the time of crash (>or=0.50 g/l), independently of any clinical evidence and laboratory results indicating acute alcohol intoxication, is associated with specific features of patients involved, specific types of injury, and characteristics of the accident. METHODS In this prospective cohort study, the BAC was measured in adult patients who had been injured and who were admitted to an Italian emergency department within four hours after a road accident. Altogether 2354 trauma patients were included between January to December 1998 out of 2856 eligible subjects. RESULTS BAC exceeded 0.50 g/l in 425 subjects (18.1%), but was in a toxic range (>1.00 g/l) in only 179 subjects (7.6%). BAC positivity was significantly more common in men, in young subjects, in subjects driving cars or trucks, and in persons involved in a crash during night time and at weekends. It was associated with higher trauma severity, but no differences were found in injury body distribution according to vehicle type. In multivariate logistic regression analysis, the risk of a positive BAC in injured patients at the time of crash was independently associated with night time (odds ratio: 3.48; 95% confidence intervals: 2.46 to 4.91), male sex (3.08 (2.36 to 4.01)), weekend nights (1.21 (1.05 to 1.41)), and age (0.92 (0.86 to 0.99) per decades). CONCLUSION In injured patients after a road accident, a BAC at the time of crash in a non-toxic range (>or=0.50 g/l) is associated with specific characteristics of crash, as well as increased risk of higher trauma severity. More careful monitoring is needed in young men during weekend nights for highest risk of BAC positivity after a road accident.