Relationship between social determinants of health and hospitalizations and costs in patients with major depressive disorder.

Background: The relationship of patient characteristics and social determinants of health (SDOH) with hospitalizations and costs in patients with major depressive disorder (MDD) has not been assessed using real-world data.

Objective: To identify factors associated with higher hospitalizations and costs in patients with MDD.

Methods: A retrospective observational study identified patients aged 18 years and older newly diagnosed with MDD between July 1, 2016, and December 31, 2018. SDOH were linked to patients at the "near-neighborhood" level. Multivariable models assessed association of patient characteristics with hospitalizations (incidence rate ratios [95% CI]) and costs (cost ratios [95% CI]).

Results: Of 1,958,532 patients with MDD, 49.6% had Commercial and 50.4% Medicaid insurance; mean ages were similar (43.9; 43.4) with more female patients (67.6%; 70.5%). MDD patients with Commercial insurance had a mean household income of $75,044; 53.2% were married; 76.5% owned their home; 64.4% completed high school or less; and 2.8% had limited English-language proficiency (LEP). Patients covered by Medicaid had a household income of $46,708; 68.1% lived alone with 41.6% married; 54.6% owned their home; more than 4-in-5 patients (80.8%) completed high school or less, and 6.3% had LEP. Nearly one-third of Medicaid insured patients with MDD had at least 1 hospitalization (29.6%) with a mean length of stay 6.8 days; total health care costs were $21,467 annually. Commercially insured patients with MDD had 14.7% hospitalization rates with a length of stay of 5.9 days; total costs were $14,531. Multivariable models show female patients are less likely (Commercial 0.87; Medicaid 0.80; < 0.05), and patients with more comorbidities are more likely to be hospitalized (Commercial 1.33; Medicaid 1.27; < 0.05). All treatment classes relative to antidepressants only increased likelihood of hospitalizations-particularly antipsychotic+antianxiety use (Commercial 2.99; Medicaid 2.29)-and costs (Commercial 2.32; Medicaid 2.00) (all < 0.05). Household income was inversely associated with hospitalizations for both insured populations. LEP reduced the likelihood of hospitalizations by more than 70% among Medicaid patients (0.27, < 0.05) and was associated with higher costs for Commercial (2.01) but lower costs for Medicaid (0.37) ( < 0.05). Living in areas with no shortage of mental health practitioners was associated with higher hospitalizations and costs.

Conclusions: We identified patient characteristics associated with higher rates of hospitalizations and costs in patients with MDD in 2 insured populations. Female sex, higher comorbidities, and living in areas with no shortage of mental health practitioners were associated with higher hospitalizations and costs, whereas income was inversely associated with hospitalizations. The findings suggest disparities in access to care related to income, LEP, and availability of mental health practitioners that should be addressed to assure equitable care for patients with MDD.