What is the risk of returning to the emergency department within 30 days for patients diagnosed with substance-induced psychosis?

Objectives The primary objective of this study was to measure the risk of return Emergency Department (ED) visits in patients presenting to the ED with a diagnosis of substance-induced psychosis. Secondary objectives included: (1) describing the characteristics of patients returning within 30 days to the ED with substance-induced psychosis, and (2) identifying risk factors associated with such ED return. Methods At two urban sites from January 1, 2018 to December 31, 2019, we included consecutive patients presenting to the ED with substance-induced psychosis defined by their ED discharge diagnosis of psychosis and clinical evidence of substance use. We described ED resources utilized by this patient population including ED time and disposition then subsequently described return visits within 30 days and characteristics among those patients who returned. Results We identified 611 unique patients presenting with substance-induced psychosis, with 813 total ED visits. The median age was 35 years (IQR 28-45), 71.4% (n = 436) were male, and 44.8% (n = 274) were homeless. The median ED length of stay was 619 min (IQR 313-898), and 48.4% (n = 296) were admitted to hospital. Forty percent of patients (n = 237) returned to the ED within 30 days of the index substance-induced psychosis visit, 116 (18.9%) returning more than once. Of these return visits, 74 (31.2%) were for recurrent substance-induced psychosis. Younger age, female gender, no opioid use, and no prior history of bipolar disorder were identified as common characteristics among those returning to the ED with substance-induced psychosis. Conclusions In ED patients with substance-induced psychosis, nearly half of all patients were admitted to hospital, 40% had a 30 days return ED visit, and one-third of those were for substance-induced psychosis. We identified clinically relevant factors common to those returning with recurrent substance-induced psychosis.