134 Risk Factors for Admission in Emerging Adults (18-25) With Asthma Seeking Care in Urban Emergency Department

Abstract

32 states have expanded Medicaid eligibility under the Affordable Care Act (ACA). Prior research indicates that patients who gain Medicaid through expansion efforts increase their use of health services in all settings, including the emergency department (ED). In addition to expanding insurance access, the ACA introduced incentives to steer patients towards less costly care, but relatively little is known about how this has influenced the way patients engage with hospital care. We examined the changes in hospital utilization among the uninsured in Maryland, which expanded Medicaid eligibility and launched a state insurance exchange in January 2014.Methods: We performed a retrospective analysis of all-payer administrative claims for 2013-2014 from the Health Services Cost Review Commission database, which tracks unique patients across all Maryland hospitals longitudinally. We created a baseline cohort of all Maryland residents who were hospitalized or visited any hospital as an outpatient in 2013 and were uninsured for all encounters in 2013. A difference-in-differences quasi-experimental approach was used to analyze changes in utilization in 2014 after insurance expansion among this uninsured cohort in comparison to baseline insured patients. Both groups were propensity score matched for individual and home zip code demographic factors and the Elixhauser comorbidity index. We used the Billings algorithm to classify ED visits.Results: The percentage of Maryland ED visits that were uninsured declined from 15% in 2013 to 11% in 2014. Of the 162,755 uninsured patients who were hospitalized or visited a hospital as an outpatient in Maryland in 2013, 58% were male, 46% were black, 34% were white, 61% were age 20-44, and 68% had an Elixhauser score of 0. Two-thirds did not return to a Maryland ED in 2014, while 10% returned with commercial insurance, 10% returned with Medicaid, and 12% returned uninsured. Over 99% (161,613) of these uninsured patients were propensity score matched with insured patients from a pool of 1,772,594. The difference-in-difference change (ie, the adjusted between-group difference in the change from 2013 to 2014) for the uninsured cohort was -0.08 (95% confidence interval -0.09 to -0.06) ED visits per patient, consistent with a 6% (5% to 8%) decline from baseline (p0.05), and ED visits for substance abuse dropped 39% (30% to 48%). These changes in ED utilization were accompanied by a large increase in inpatient and other outpatient utilization among the uninsured. Conclusion:In the first year after Medicaid expansion in Maryland, there was a modest decline in ED utilization among the previously uninsured accompanied by a large increase in other hospital utilization. Insurance expansion may provide an opportunity to change how patients engage with hospital care.