Impact of the enhanced Fatality Analysis Reporting System on drug detection in fatally injured drivers

The prevalence of drugged driving has been increasing in the United States. In 2018, the Fatality Analysis Reporting System (FARS) enhanced toxicology data collection by expanding the number of reportable nonalcohol drugs beyond the previous limit of three. In this repeated cross-sectional study, we used difference-in-differences analyses, Poisson regression, and joinpoint regression to assess changes in the detection of alcohol and nonalcohol drugs among fatally injured drivers before (2013-2017; n = 68,741) and after (2018-2022; n = 69,764) the enhancement. The prevalence of alcohol remained stable over time, averaging 37 %, with similar values in 2013-2017 (37.1 %) and 2018-2022 (37.9 %). In contrast, the prevalence of any nonalcohol drug increased from 39.9 % to 55.0 % (p < 0.001). The prevalence of marijuana rose from 14.4 % to 26.4 % (p < 0.001), stimulants from 9.3 % to 25.1 % (p < 0.001), and depressants from 9.1 % to 13.7 % (p < 0.001). Between the two periods, the prevalence of ≥ 1 nonalcohol drug increased by 9 %, with marijuana and stimulants showing the largest gains. Drivers who tested positive for both alcohol and marijuana increased from 8.3 % to 11.8 % (p < 0.001). The proportion that tested positive for ≥ 2 nonalcohol drugs rose from 13.6 % to 19.2 % (p < 0.001), and for ≥ 3 drugs from 2.0 % to 5.8 % (p < 0.001). The mean number of nonalcohol drugs detected increased from 1.36 to 1.50 (p < 0.001). In adjusted models, the odds of detecting any nonalcohol drug associated with the enhanced toxicology data collection increased 42 % [adjusted odds ratio (aOR) 1.42, 95 % confidence interval (CI) 1.37, 1.47], with greater increase in detecting ≥ 2 drugs (aOR 1.46, 95 % CI 1.40, 1.52) and ≥ 3 drugs (aOR 3.01, 95 % CI 2.80, 3.24). These findings highlight improved detection of polysubstance use among fatally injured drivers following the adoption of a comprehensive toxicological testing data file by FARS in 2018.