Abstract
BACKGROUND: The Affordable Care Act has added millions of new Medicaid enrollees to the health care system. These patients account for a large proportion of emergency department (ED) utilization. OBJECTIVE: Our aim was to characterize this population and their ED use at a national level. METHODS: We used the 2010 National Hospital Ambulatory Medical Care Survey (NHAMCS) to describe demographics and clinical characteristics of nonelderly adults (≥18 years old and ≤64 years old) with Medicaid-covered ED visits. We defined frequent ED users as individuals who make ≥4 ED visits/year and business hours as 8 am to 5 pm. We used descriptive statistics to describe the epidemiology of Medicaid-covered ED visits. RESULTS: NHAMCS included 21,800 ED visits by nonelderly adults in 2010, of which 5,659 (24.09%) were covered by Medicaid insurance. Most ED visits covered by Medicaid were made by patients who are young (25 and 44 years old) and female (67.95%; 95% confidence interval [CI] 66.00-69.89). A large proportion of the ED visits covered by Medicaid were revisits within 72 h (14.66%; 95% CI 9.13-20.19) and from frequent ED users (32.32%; 95% CI 24.29-40.35). Almost half of all ED visits covered by Medicaid occurred during business hours (45.44%; 95% CI 43.45-47.43). CONCLUSIONS: The vast majority of Medicaid enrollees who used the ED were young females, with a large proportion of visits occurring during business hours. Almost one-third of all visits were from frequent ED users.