Depression in Emergency Department Patients and Association With Health Care Utilization

Background: Depression is one of the most common illnesses in the United States, with increased prevalence among people with lower socioeconomic status and chronic mental illness who often seek care in the emergency department (ED). We sought to estimate the rate and severity of major depressive disorder (MDD) in a nonpsychiatric ED population and its association with subsequent ED visits and hospitalizations. Methods: This prospective cohort study enrolled a convenience sample of English-speaking adults presenting to an urban academic medical center ED without psychiatric complaints between January 1, 2015, and September 21, 2015. Patients completed a computerized adaptive depression diagnostic screen (CAD-MDD) and dimensional depression severity measurement test (CAT-DI) via tablet computer. Primary outcomes included number of ED visits and hospitalizations assessed from index visit until January 1, 2016. Negative binomial regression modeling was performed to assess associations between depression, depression severity, clinical covariates, and utilization outcomes. Results: Of 999 enrolled patients, 27% screened positive for MDD. The presence of MDD conveyed a 61% increase in the rate of ED visits (incidence rate ratio [IRR] = 1.61, 95% confidence interval [CI] = 1.27 to 2.03) and a 49% increase in the rate of hospitalizations (IRR = 1.49, 95% CI = 1.06–2.09). For each 10% increase in MDD severity, there was a 10% increase in the relative rate of subsequent ED visits (IRR = 1.10, 95% CI = 1.04 to 1.16) and hospitalizations (IRR = 1.10, 95% CI = 1.02 to 1.18). Across the range of the severity scale there was over a 2.5-fold increase in the rate of ED visits and hospitalization rates. Conclusions: Rates of depression were high among a convenience sample of English-speaking adult ED patients presenting with nonpsychiatric complaints and independently associated with increased risk of subsequent ED utilization and hospitalization. Standardized assessment tools that provide rapid, accurate, and precise classification of MDD severity have the potential to play an important role in identifying ED patients in need of urgent psychiatric resource referral.