Substance Use and Motor Vehicle Accident Mortality in the United States: A 22-Year National Analysis

Background: Motor vehicle accidents (MVAs) are a major cause of unintentional injury deaths in the United States. Substance use, particularly alcohol and cannabis, is a well-established contributor to impaired driving and fatal MVAs. This study aimed to analyze mortality trends from MVAs associated with substance use from 1999 to 2020 in the United States. Methods: We conducted a retrospective analysis using the CDC WONDER database, examining death certificates from 1999 to 2020 that recorded both MVAs and substance use in individuals aged ≥15 years. Data were stratified by sex, age group (15-64 and ≥65), race (white and black), and US census region. Age-adjusted mortality rates (AAMRs) were calculated, and temporal trends were analyzed using the Mann-Kendall trend test. Jointpoint regression analysis was used to calculate Average Annual Percentage Change (AAPC). Results: A total 24 152 deaths were recorded, with an overall AAMR of 0.46 per 100 000 population. While overall trends were stable, a significant increase in AAMR was observed among women (AAPC: 3.04% increase; P = .002), particularly white women (+4.3%) and women in the West (+2.0%). Older men (≥65) also experienced a significant rise (τ: 0.63; P < .001). Men consistently had higher mortality than women across all demographics ( P < .001). Regionally, men in the Northeast experienced a significant decline (τ: −0.57). Conclusion: While total substance-related MVA mortality remained stable, the rising mortality among women, older men, and certain subgroups highlights shifting risk profiles. These findings underscore the need for targeted, demographically inclusive public health strategies and equitable resource allocation to reduce preventable deaths.