One-year mortality of emergency department patients with substance-induced psychosis

OBJECTIVES: Psychosis is a well established complication of non-prescription drug use. We sought to measure the 1-year mortality of emergency department patients with substance-induced psychosis (SIP). METHODS: This study was a multi-centre, retrospective electronic medical records review of patients presenting to the ED with substance-induced psychosis (SIP). We interrogated the hospital ED database from Jan 1, 2018 and Jan 1, 2019 to identify consecutive patients. All patients were followed for one year from index visit, and classified as alive/dead at that time. Patients were included in the study if they met the following criteria: 1) ED discharge diagnosis of psychosis NOS and a positive urine drugs of abuse screen (UDAS) or the patient verbally endorsed drug use, or 2) Mental disorder due to drug use and “disorganized thought”, “bizarre behavior” or “delusional behavior” documented in the chart and one or more of the following criteria: a) arrival with police, b) mental health certification, c) physical restraints, d) chemical restraints. We excluded patients who were not British Columbia residents, since we were unable to ascertain if they were alive or dead at 1 year from their index ED visit. Primary statistical analysis was logistic regression for risk of death in 1 year, based on plausible risk factors, selected a priori. RESULTS: We identified 813 presentations for SIP (620 unique patients). The median age of the entire cohort was 35 years (IQR 28–44), and 69.5% (n = 565) were male. Thirty five patients (4.3%; 95% CI 3.2–5.9) had died one year after their initial presentation to the ED for SIP. Separate multivariable logistic regression analyses, controlling for age, demonstrated schizophrenia (OR 4.2, 95% CI 1.8–11.1) significantly associated with increased 1-year mortality. CONCLUSIONS: In our study of patients presenting to the ED with SIP, the 1-year mortality was 4.3%. Controlling for age, schizophrenia was a notable risk factor for increased 1-year mortality.