Background
Substance use can elevate the risk and severity of domestic assault. Using US emergency medical services (EMS) data, this study examined domestic assault severity and associated substance use across the life course.
Methods
This study used 2019 National Emergency Medical Services Information System (NEMSIS) data to describe patient substance use and injury severity among domestic assault cases (n=176 931). Substance use was compared across demographic groups and severity of injury (patient acuity, neurological impairment and transport to trauma centre). Multinomial regression analysed the association between substance use and injury severity indicators.
Results
While alcohol was the most frequent substance used, drug use and combined use were more common with severe injuries. Male patients had higher odds of all severe injury indicators with drug use or combined use. Female patients had increased odds of severe injury with any substance use. When stratified by sex, alcohol use significantly contributed to injury differences between male and female patients. Specifically, alcohol use increased the risk of severe injuries for female patients and decreased or had no impact on the risk of severe injuries for male patients.
Discussion
NEMSIS data showed that substance use increased the risk of severe injury from domestic assault across every stage of life, furthering the call for gender-specific interventions in emergency medical care that address these co-occurring issues to prevent severe violence.

