Alcohol is a significant public health issue, according to the World Health Organization. Our study aims to analyze the correlation between blood alcohol concentrations (BACs) of drivers, their demographic features, and the possible underestimation of BACs due to the time elapsed between hospital admission and blood sampling. Methods: This study includes patients evaluated for BAC levels in the emergency department (ED) of Fondazione Policlinico Universitario A. Gemelli IRCCS from January 2013 to December 2016. BAC levels were compared in patients involved in road crashes according to age group, sex, and time of the accident. The delays in blood sampling and BAC measurement in the ED were recorded for each patient. The time between the accident and access to the hospital in most cases was unknown. Results: A total of 398 patients were included in the analysis, 107 of them had BACs more than 0.05 g/L., and 86 of these individuals had BAC levels more than 0.5 g/L. Road accident patients had higher rates of positive BAC readings at night and on weekends. A significant delay in blood sampling for BAC determination was observed. Discussion: This study demonstrates a critical bias due to the arrival time at the ED and the delay in blood sampling that inevitably influences and underestimates the BAC, resulting in possible false negative results (BAC values below the cutoff). Zero tolerance or a retrospective BAC calculation could mitigate this bias. It is necessary to implement preventive strategies to reduce instances of driving under the influence (DUI) of alcohol.
Keywords: Blood alcohol concentration (BAC); alcohol-related accidents; back-calculation; forensic toxicology; motor vehicle accidents (MVAs); zero tolerance.