Alcohol-impaired driving and drinking at private residences

Although drunk driving prevention and enforcement programs often focus on people who drink at bars and restaurants, drinking at home is strongly associated with driving after drinking and impaired driving, and may account for about a third of all drink driving events, according to a new study from the Prevention Research Center at the Pacific Institute for Research and Evaluation.

The data used for this study were obtained from a telephone survey of 8,553 Californians age 18 and older. Respondents were asked questions about where and how much they used alcohol in the previous month, whether they had driven a car within four hours of drinking, and whether they had driven after they felt they had drunk "too much" to drive safely. (Each respondent decided how much was "too much.")

The results of the study indicate that far more people drink frequently at home and far fewer people drink less frequently at restaurants and bars. 73% of drinking occasions were in the home while only 9% were at restaurants, 5% at bars, and 5% at private parties.

As everyone would expect, driving after drinking was much more likely to occur after any single drinking event that occurred outside the home at a bar or restaurant. However, while drinking at home was rarely associated with driving after drinking or impaired driving, there were so many of these events that drinking at home led to substantial numbers of drunken driving events.

Using as an example a typical city in California 100,000 people, we would expect to see 26,097 events of driving after drinking related to drinking at bars and 31,602 such events related to drinking at restaurants. But the same city would also see 15,411 driving after drinking events related to drinking in the home and 19,168 events related to drinking at private parties.

The study—conducted by a group led by Dr. Paul Gruenewald—suggests that drink driving prevention programs should look beyond those who drink in bars or restaurants. "'Prevention in place' is the new mantra for modern environmental prevention programs," Gruenewald says. "Our ability to use social media and other methods to reach out to drinkers in all environments can be extended to encourage safe drinking practices in the home and other contexts."