Age-related differences in risks of drinking and driving in gender and ethnic groups.

We examine the extent to which empirically observed age-related differences in rates of drinking and driving can be explained by concurrent differences in drinking patterns. Building on previous research showing significant age differences in drinking patterns between men and women and among three ethnic groups, Whites, Blacks, and Hispanics, our study considers whether there are unique gender and ethnic group differences in patterns of drinking and driving. Data were from 4395 respondents 12 to 80 years old in a general population survey of 20 urban areas in the United States. During the month preceding the interview, 1130 (25.7%) of all respondents had driven after having one or more drinks. Drinking pattern measures included drinking frequency, average drinking quantity, and the variance in the number of drinks consumed per occasion. To assess the relationships of drinking patterns to drinking and driving across age groups, two sets of analyses were conducted, one set in which age differences in drinking patterns were statistically controlled and one set in which they were not. Although the statistical control for drinking patterns reduced age differences between gender and ethnic groups, it did not eliminate them. The reduction demonstrated that part of observed group differences in driving after drinking over age among gender and ethnic groups is due to age-related differences in drinking patterns. However, despite controlling drinking patterns young respondents remained more likely to drink and drive. A supplementary analysis of self-reported incidents of driving while intoxicated (i.e., driving after having five or more drinks) further indicated that, controlling for drinking patterns, young respondents are most at risk.