Abstract
BACKGROUND: Alcohol-impaired driving remains a leading cause of road traffic deaths worldwide, yet despite widespread adoption, the effectiveness of national blood alcohol concentration (BAC) limits across diverse structural conditions and population risks remains poorly understood. METHODS: We conducted a cross-national multilevel analysis of 165 countries using 2019 data on alcohol-attributable traffic mortality rates (ATMRs), national legal BAC limits, and structural country-level indicators. The primary outcome was ATMRs, defined as age-standardized death rates per 100,000 population among individuals aged 15 and older. Key predictors included national BAC limits, sex, and their interaction. Models were adjusted for national income, healthcare system infrastructure, gender inequality, and per capita alcohol consumption. FINDINGS: Lower national BAC limits were associated with lower ATMRs, with significantly stronger effects observed among males versus females (β = -2.58, p < 0.01). Structural factors, including lower national income (β = -0.31, p < 0.01), greater gender inequality (β = 1.61, p < 0.01), and higher alcohol consumption (β = 0.16, p < 0.001) each predicted higher ATMRs. Our final model explained 71% of the variance in ATMRs. INTERPRETATION: ATMRs represent a preventable global burden, with World Health Organization (WHO) BAC guidelines being exceeded in ∼30% of countries examined. While lower BAC limits reduce ATMRs overall for both women and men, men experienced a disproportionately higher share of the mortality burden. Further reduction in ATMRs would be maximized by considering country-level structural factors. FUNDING: NIH T32AA029259(CLJC), U54AA027989(SAM), K01AA029706(YZ), R01AA030971(TLV), Office of the Assistant Secretary of Defense for Health Affairs W81XWH-22-2-0081, PASA3(MRP/AAM) and Veterans Affairs VISN1-CDA(MRP).