Citation

Evans L, Frick MC. Proc. Assoc. Adv. Automot. Med. Annu. Conf. 1991; 35: 179-195.

Copyright

(Copyright © 1991, Association for the Advancement of Automotive Medicine)

DOI

unavailable

PMID

unavailable

Abstract

Although alcohol's effect on the risk of being involved in a traffic crash is well known, its influence on the risk of death, given that a crash has occurred, is more uncertain. One study published a few years ago finds that alcohol increases the risk of death in a crash. The present study examines alcohol's effect on fatality risk in a crash using data and methods independent of the previous study, and provides estimates as a function of Blood Alcohol Concentration (BAC). Data for drivers with measured BAC who were fatally injured in a two-car crash were selected from the Fatal Accident Reporting System (FARS). The study uses two sets of fatal crashes. For one, the probability that a BAC = 0 driver was killed is low, so that if alcohol increased fatality risk, this would generate additional fatalities at higher BAC levels. For the other set of crashes, fatality risk to the BAC = 0 driver was sufficiently close to 100% that the number of fatalities could not be increased much more by other factors. Dividing the fatalities which can be affected by alcohol by those which cannot provides a measure of how alcohol influences fatality risk. The study confirms the earlier finding that alcohol can also substantially increase the probability of being killed in a crash. It is found that a driver with BAC = 0.1% is (1.9 ± 0.2) times as likely as is a BAC = 0 driver to be killed in the same crash. The corresponding ratio for a BAC = 0.25% driver is (3.3 ± 0.5). The above applies for crashes in which the BAC = 0 driver has a relatively low (< 10%) probability of fatality. As crash severity increases and the BAC = 0 driver's fatality risk approaches 100%, the risks become more similar. While derived using the "laboratory" of traffic, there does not appear to be any obvious reason why the results should not apply to physical trauma in general, so a BAC of 0.1% doubles the risk of death from a given impact, and a BAC of 0.25% triples the risk