A case-control study of motorcycle crashes was undertaken in which injured riders and pillion passengers from 222 crashes in Melbourne, Australia were compared with 1200 motorcyclists riding through the crash sites at the same time of day and week. Having a BAC greater than zero was associated with a fivefold increase in the odds of crashing compared to having a BAC of zero. The increase in risk associated with a BAC of greater than 0.05% was about forty-fold. Night-time crashes were more likely to involve alcohol and had fewer controls than daytime crashes. Alcohol may play a smaller role in motorcycle crashes than in car crashes because of the largely daytime pattern of motorcycle riding. Having a positive BAC was associated with greater riding experience, unlicensed riding, riding a borrowed motorcycle, carrying a pillion passenger, illicit drug use, excessive speed and single-vehicle crashes. The odds ratios related to BAC level were possibly reduced by matching cases and controls on time of day and day of week and by the greater range of BAC values for cases than controls.
Abstract