Adult Medicaid enrollees are more likely to have mental health disorders (MHDs) than privately insured patients and also have high rates of emergency department (ED) visits for ambulatory care–sensitive conditions (ACSCs). We aimed to evaluate the association of MHD and insurance type with ED admissions for ACSC in the United States.

We conducted a cross-sectional study of ED visits made by adults aged 18 to 64years using the corrected 2011 National Emergency Department Survey. Using multivariable logistic regression analysis, we controlled for sociodemographics and clinical variables to determine the association between insurance type, MHD, Medicaid, and MHD (as an interaction variable) and ED admissions for ACSC.

There were 131 million ED visits in 2011; after exclusions, 1.4 million admissions were included in our study. Of all ED visits, 44.7% had an MHD, of which 49.9% were covered by Medicaid and 38.1% were covered by private insurance. A total of 32.6% (95% confidence interval, 32.5%-32.7%) of ED admissions were for an ACSC. Medicaid-covered ED visits were more likely to result in ACSC hospital admission (odds ratio, 1.32; 95% confidence interval, 1.30-1.35) compared with visits covered by private insurance. Among patients with MHD, those with Medicaid insurance had 1.6 times the odds of ACSC admission compared with those privately insured.

Among all ED admissions, patients covered by Medicaid are more likely to be admitted for an ACSC when compared with those covered by private insurance, with a larger association being present among patients with MHD comorbidities.