Background: This study aims to assess the rural-urban differences between substance use and crash injury severity among older adults.
Methods: This single-year cross-sectional analysis pooled the 2019 data from the National Emergency Medical Service Information System. We measured injury severity (low acuity, emergent, critical, and fatal) as predicted by substance use, defined as self-reported or officer-reported alcohol and/or drug use. We controlled for age, sex, road user type, anatomical injured region, revised trauma score, location (scene) of the injury, and the time of the day. We stratified by rurality/urbanicity and performed a partial proportional ordinal logistic regression. We reported the odds of worse injury outcomes (emergent, critical, and fatal injuries) compared to low acuity injuries and the predicted probabilities of each injury category by rurality/urbanicity.
Results: Our sample consisted of 58,238 older adults, who sustained crash injuries. Approximately 69%, 25%, 5%, and 1% sustained low acuity, emergent, critical, and fatal injuries, respectively. Substance use was reported in approximately 4% of the sample population, and this proportion did not significantly differ across rural-urban areas. After controlling for patient and injury characteristics, substance use was associated with 45% increased odds of emergent, critical, and fatal injuries compared to low acuity injuries across all areas. The predicted probabilities of critical and emergent injuries increase from urban to suburban and rural areas.
Conclusion: Substance use is associated with worse geriatric crash injury severity and the predicted probabilities of substance use-related emergent and critical crash injuries increase from urban to rural areas.