Violent reinjury and mortality among youth seeking emergency department care for assault-related injury: a 2-year prospective cohort study.

IMPORTANCE Violence is a leading cause of morbidity and mortality among youth, with more than 700000 emergency department (ED) visits annually for assault-related injuries. The risk for violent reinjury among high-risk, assault-injured youth is poorly understood. OBJECTIVE To compare recidivism for violent injury and mortality outcomes among drug-using, assault-injured youth (AI group) and drug-using, non-assault-injured control participants (non-AI group) presenting to an urban ED for care. DESIGN, SETTING, AND PARTICIPANTS Participants were enrolled in a prospective cohort study from December 2, 2009, through September 30, 2011, at an urban level I ED and followed up for 24 months. We administered validated measures of violence and substance use and mental health diagnostic interviews and reviewed medical records at baseline and at each point of follow-up (6, 12, 18, and 24 months). EXPOSURE Follow-up over 24 months. MAIN OUTCOMES AND MEASURES Use of ED services for assault or mortality measured from medical record abstraction supplemented with self-report. RESULTS We followed 349 AI and 250 non-AI youth for 24 months. Youth in the AI group had almost twice the risk for a violent injury requiring ED care within 2 years compared with the non-AI group (36.7% vs 22.4%; relative risk [RR], 1.65 [95% CI, 1.25-2.14]; P<.001). Two-year mortality was 0.8%. Poisson regression modeling identified female sex (RR, 1.30 [95% CI, 1.02-1.65]), assault-related injury (RR, 1.57 [95% CI, 1.19-2.04), diagnosis of a drug use disorder (RR, 1.29 [95% CI, 1.01-1.65]), and posttraumatic stress disorder (RR, 1.47 [95% CI, 1.09-1.97]) at the index visit as predictive of ED recidivism or death within 24 months. Parametric survival models demonstrated that assault-related injury (P<.001), diagnosis of posttraumatic stress disorder (P=.008), and diagnosis of a drug use disorder (P= .03) significantly shortened the expected waiting time until the first ED return visit for violence or death. CONCLUSIONS AND RELEVANCE Violent injury is a reoccurring disease, with one-third of our AI group experiencing another violent injury requiring ED care within 2 years of the index visit, almost twice the rate of a non-AI comparison group. Secondary violence prevention measures addressing substance use and mental health needs are needed to decrease subsequent morbidity and mortality due to violence in the first 6 months after an assault injury.