International drink-driving policy research generally focuses on aggregate outcomes (e.g., rates of crashes, fatalities) without emphasizing secondhand alcohol-related vehicular harms. In contrast, we investigate associations between drink-driving policies and harms involving another driver's impairment.
Alcohol's harms to others (AHTO) survey data from 12 countries (analytic N = 29,616) were linked to national alcohol policy data from the World Health Organization. We examined separately associations of two 12-month driving-related AHTOs (passenger with an impaired driver; vehicular crash involving someone else's drink driving) with 3 national drinking-driving policies-legal blood alcohol concentration (BAC) limits, use of random breath testing, use of sobriety checkpoints, and comprehensive penalties for drink-driving (community service, detention, fines, ignition interlocks, license suspension/revocation, mandatory alcohol treatment, vehicle impoundment, and penalty point system), plus 2 alcohol tax variables (having excise taxes and value-added tax [VAT] rate). Multilevel logistic regression addressed clustering of individuals within countries and subnational regions, while adjusting for individuals' gender, age, marital status, risky drinking, and regional drinking culture (% male risky drinkers in sub-national region).
Controlling for national-, regional-, and individual-level covariates, comprehensive penalties were significantly and negatively associated with both outcomes; other vehicular policy variables were not significantly associated with either outcome. A society's VAT rate was negatively associated with riding with a drunk driver. Regional male drinking culture was positively associated with riding with an impaired driver, but was not significantly associated with being in a vehicular crash due to someone else's drinking. In both models, being male, being younger, and engaging in risky drinking oneself each were positively associated with vehicular harms due to someone else's drinking.
Although results are associational and not causal, comprehensive penalties may be promising policies for mitigating driving-related harms due to another drinker. Higher VAT rate might reduce riding with a drunk driver.