Portal de Periódicos da CAPES

Accidents, Alcohol and Single-Cause Explanations; Lessons from the Grand Rapids Study

1968; Volume: 29; Issue: S4 Linguagem: Inglês

10.15288/qjsas.1968.s4.212

1946-7222

Richard Zylman,

Substance Abuse Treatment and Outcomes

Although many investigations have demonstrated a positive relationship between traffic accidents and the alcohol level in the driver's blood, most have not considered the blood alcohol concentration (bac) in control or population-at-risk groups, i.e., people using the same roads at the same hours without accident involvement. A study in Grand Rapids, Mich., using a large control group, implicated 8 other factors in addition to alcohol as being associated to some degree with accidents. Time of day: Of 5985 subjects in the accident group (ag) and 7590 in a control group (cg), 9.6% and 3.2% respectively had bacs of 0.05% or higher over the 24-hr period. From midnight to 3 am, however, the percentages with these bacs were 41 and 17, respectively; from 3 to 6 am, 47 and 22; from 3 to 6 pm, 6.5 and 1.7; from 6 pm to midnight, 16 and 4.2. In terms of ratios between the ag and cg, the same amount of alcohol is more likely to cause a driver to be involved in an accident during periods of dense rather than light traffic. Drivers with bacs of over 0.08%, however, were significantly overrepresented in accidents during the postmidnight as well as peak-traffic periods. Age was second only to alcohol in predicting accidents. Those aged 16 to 24 and those 70 and over were overrepresented in the ag. Those least likely to have accidents were aged 25 to 69, up to a bac of 0.05%, after which the difference in accident experience was no longer statistically significant. Thus the effects of age on accidents are modified by the effects of alcohol. Occupation: Low occupational categories had the highest accident experience but also a disproportionate share of high bacs, even in the cg. Race: Non-Whites appeared in accidents one-third more often than would be expected, because of socioeconomic differences: unskilled Whites compared to unskilled non-Whites in the same age class had about equal accident experiences. Non-Whites constituted only 7% of the cg but provided 24% of bacs of 0.08% and over. Marital status: Married drivers had accidents less often than all other categories up to a bac of 0.04%. Sex: When only those with zero bacs were considered, women had slightly more accidents than men; when only positive bacs were considered, the sex differential disappeared. Driving experience was inversely associated with accident experience; the ag contained 45% more drivers who drove 0 to 1000 miles per year than the cg. It was the only variable other than alcohol that remained statistically significant during the midnight to 3 am period when drivers of less than 1000 miles per year appeared in the ag 73% more often than in the cg. Only at bacs above 0.10% did high-mileage drivers have about as many accidents as low-mileage drivers. Drinking experience was inversely associated with accident experience.