A cohort study of predictors of short-term nonfatal suicidal and self-harm events among individuals with mental health disorders treated in the emergency department.

BACKGROUND

Patients presenting to emergency departments (EDs) for mental health problems have an elevated short-term risk of repeat ED visits, subsequent hospitalization, and suicide.

OBJECTIVE

Use health records to identify predictors of nonfatal suicidal or self-harm events following emergency department visits of individuals with mental health disorders.

METHODS

Electronic health record data from 2015 to 2022 were used to identify ED visits with mental health diagnoses for individuals 10 and older; extract 408 potential predictors including demographic, historical and baseline clinical characteristics from structured and unstructured data; and subsequent suicidal and self-harm events. We constructed a series of progressively additive logistic regression and gradient tree boosting (GTB) models to evaluate how groups of clinical features influenced likelihood of a nonfatal event 180-days after an ED visit.

RESULTS

Records identified 2,445,597 ED episodes and 176,000 subsequent suicidal or self-harm events within 180-days. Individuals experiencing an event relative to those without an event were less likely to be > 65 (3.6 % vs 16.7 %; h = 0.46), more likely to be male (55.7 % vs 40.8 %; h = 0.30) and covered by Medicaid (61.5 % vs 42.2 %, h = 0.39). The final model with 408 clinical features resulted in an AUC of 0.851 (logistic regression) and 0.863 (GTB). Diagnoses of bulimia nervosa (OR = 1.84, p < .0001) and cutting (OR = 2.62, p < .0001) were most highly associated with any subsequent event and suicidal self-harm, respectively.

CONCLUSION

Machine learning algorithms effectively predicted nonfatal suicide-related events within six months following ED visits among individuals with mental health disorders highlighting the importance of suicide symptom focused assessment and prevention efforts during routine emergency mental healthcare, particularly for patients with bulimia nervosa.