Age, sex, and blood alcohol concentration of killed and injured drivers, riders, and passengers.

The relationships between type of road user, sex, age, and blood alcohol concentration (BAC) were examined among 1,389 adult vehicle occupants and motorcyclists fatally injured in crashes within South Australia from 1985 to 1992, inclusive, and among 1,573 adult vehicle occupants and motorcyclists admitted to a Level-1 trauma centre from August 1985 to July 1987. The relationships between BAC and both day of week of crash and the number of vehicles involved were determined among fatalities, whereas among admissions, duration of hospitalization and type of unit to which the casualty was admitted were also examined. BACs of .08 g/100 mL or higher were found in 38% of killed and 30% of injured drivers, 37% and 27% of passengers, and 35% and 22% of male motorcycle riders. Alcohol involvement was almost nonexistent among the elderly. The finding that the proportion of injured motorcyclists was similar to that of drivers is consistent with motorcyclists' increased risk of injury even in relatively minor crashes. Male motorcycle riders were found to be significantly younger than male drivers. They were also significantly less likely to have been drinking and, if they had been drinking, their mean BAC was significantly lower. The results are also consistent with the well-established observations that alcohol involvement is greater in single-vehicle crashes and in crashes occurring on weekends. Average duration of hospitalization was not found to differ between types of road user or between those with a BAC above and below .08 g/100 mL.