Health outcomes associated with emergency department visits by adolescents for self-harm: A propensity-matched cohort study

Abstract

BACKGROUND: Self-harm is increasing among adolescents, and because of changing behaviours, current data are needed on the consequences of selfharm. We sought to investigate the trends related to hospital presentation, readmission, patient outcome and medical costs in adolescents who presented with self-harm to the emergency department. METHODS: We used administrative data on 403?805 adolescents aged 13-17 years presenting to Ontario emergency departments in 2011-2013. Adolescents with self-harm visits were 1:2 propensity matched to controls with visits without self-harm, using demographic, mental health and other clinical variables. Five years afer the index presentation, hospital or emergency department admission rates for self-harm, overall mortality, suicides and conservative cost estimates were compared between the 2 groups. RESULTS: Of 5832 adolescents who visited Ontario emergency departments in 2011-2013 after self-harm (1.4% of visits), 5661 were matched to 10?731 adolescents who presented for reasons other than self-harm. Adolescents who presented with self-harm had a shorter time to a repeat emergency department or hospital admission for self-harm (hazard ratio [HR] 4.84, 95% confidence interval [CI] 4.44-5.27), more suicides (HR 7.96, 95% CI 4.00-15.86), and higher overall mortality (HR 3.23, 95% CI 2.12-4.93; p < 0.001). The positive predictive value of self-harm-related emergency department visits for suicide was 0.7%. Adolescents with self-harm visits had mean 5-year estimates of health care costs of $30?388 compared with $19?055 for controls (p < 0.001). INTERPRETATION: Adolescents with emergency department visits for selfharm have higher rates of mortality, suicide and recurrent self-harm, as well as higher health care costs, than matched controls. Development of algorithms and interventions that can identify and help adolescents at highest risk of recurrent self-harm is warranted.