Association of Depression Severity With Acute Risk of ER Visits and Hospitalizations Among Adults With Major Depressive Disorder

Introduction: Although major depressive disorder (MDD) is the leading cause of disability worldwide, the relationship between depression severity and risk of ER visit/hospitalization is unknown. This study inferred the effect of depression severity (measured by Patient Health Questionnaire-9 [PHQ-9]) on 30-day ER visits/hospitalizations among adults with MDD.

Methods: A retrospective observational study assessed adults with MDD and ≥1 PHQ-9 record (2007-2018), using the Optum® de-identified Electronic Health Record dataset. Depression severity levels were: none/minimal=0-4; mild=5-9; moderate=10-14; moderately-severe=15-19; severe=20-27. Regression models with inverse probability weighting, adjusting for baseline characteristics, estimated absolute risk at each severity level and relative risk of 30-day ER visit/hospitalizations across severity levels.

Results: Among 377,608 patients, mean(SD) age was 48.5(17.7) years; 71.7% were female. Distribution of depression severity levels was: 20.5% none/minimal, 32.6% mild, 19.3% moderate, 16.5% moderately-severe and 11.1% severe. Adjusted absolute risk of all-cause ER visits/hospitalizations was 3.7%, 4.5%, 4.4%, 5.3%, and 6.5% for none/minimal, mild, moderate, moderately-severe, and severe, respectively. Risk ratios (95% CI) for one-level depression severity changes were: 1.22 (1.16-1.29) none/minimal to mild, 0.98 (0.93-1.02) mild to moderate, 1.19 (1.13-1.25) moderate to moderately-severe, 1.24 (1.17-1.31) moderately-severe to severe. The change from none/minimal to severe resulted in 76% increased risk of ER visit/hospitalization (RR 1.76, 95% CI 1.66-1.87). Patterns were similar for Mental Health-, MDD- and Suicide Attempt/Suicidal Ideation-related ER visits/hospitalizations.

Conclusions: Increasing depression severity, especially from none/minimal to severe, leads to increased risk of short-term ER visit/hospitalization, underscoring the need for better interventions to reduce depression symptoms for patients with MDD.

This poster was presented at the 32nd annual Psych Congress, held Oct. 3-6, 2019, in San Diego, California.