Alcoholic beverage choice, risk perception and self-reported drunk driving: effects of measurement on risk analysis.

AIMS The present study examined effects of measurement on risk curve analysis in an application involving prediction of frequency and indicator measures of drunk driving with beverage-specific alcohol consumption and risk perception measures. DESIGN AND PARTICIPANTS From a 1995 in-person survey of the US adult household population (response rate = 77%) the responses of 1260 adult drivers who reported any drinking in the prior year were selected for analysis. Regression and graphical techniques were used to investigate relationships between drinking pattern, beverage choice, perception of risks of drinking before driving, and frequency of drunk driving. MEASUREMENTS Self-reported drunk driving (occurrence) was measured by a question assessing driving after drinking enough to be in trouble if stopped by the police within the prior 12 months; those affirming this (n = 191) were asked how many times they did so (frequency). Alcohol consumption was assessed by beverage and in combination. Risk perception was assessed as a factor score from three correlated measures. Demographic variables included age, ethnicity, education and income. FINDINGS Controlling for demographics, heavy beer consumption (p < 0.01) more than heavy wine (NS) or liquor/spirits (p < 0.05) intake was strongly predictive of risk perception. A regression analysis showed a significant interaction between heavy beer consumption and perceived risk (p < 0.001) in predicting reported frequency of drunk driving, after controlling for heavy beer consumption (p < 0.05), total alcohol consumption and risk perception (both ps < 0.001). No interactions were important in equivalent models predicting dichotomous occurrence. Graphic analysis showed the shape of the risk curve is altered when frequency of drunk driving is taken into account rather than simple occurrence. CONCLUSIONS Individuals' underestimation of beer's intoxicating effects, compared to other alcoholic beverage types, helps explain beer's over-representation in drinking driving violation reports. There is a need for creative public health campaigns designed to inform young men of beer's alcohol content and associated risks.