The Legal Limit: Differences in Injury Severity Score for Vehicular Crashes

In 2013, the National Transportation Safety Board advised lawmakers in the United States to reduce the legal limit of blood alcohol content (BAC) from 0.08% to 0.05%. The purpose of this research was to evaluate the rationale for reducing the legal limit of BAC to 0.05% through analysis of the relationship between BAC and injury severity. A correlational study was conducted on patients with positive BAC involved in a motor vehicular collision. Retrospective review of 446 trauma patients (aged 18-80 years) injured in a vehicular collision routinely screened for BAC was conducted. Two groups were compared: Group 1, patients with nonzero blood alcohol concentration (n = 101); and Group 2, patients with zero blood alcohol (n = 345). Standard statistical analyses were utilized. A total of 101 patients (23%) had a detectable BAC on admission. Patients with a detectable BAC were younger (33 and 44 years) and more likely to be male (27% and 16%). There was no statistically significant association between both injury severity score (ISS) and BAC or between ISS and age. There was no significant correlation between higher BAC and a higher ISS. Positive BAC alone may not affect ISS, but the potential for risk-taking behaviors by drivers under the influence may increase injury severity.