Effects of Copays on Non-Urgent ED Use in a Medicaid Population

Background: Research has shown that cost-sharing affects emergency department (ED) use, with lower enrollee cost-sharing associated with increased use. There has been specific concern about ED use in the Medicaid population, where gaining coverage has been associated with increased ED use, including for conditions better treated in a primary care setting. To promote the use of primary care and encourage appropriate use of the ED, Michigan’s 2014 Medicaid expansion program does not include copays for preventive services but does include cost-sharing for non-urgent ED visits. Enrollees with incomes at less than 100 percent of the federal poverty level incurred $3 copayment for ED use; eligible enrollees with higher incomes incurred an $8 copayment for ED use. Copayments are waived for ED use for urgent conditions and are assessed for those considered non-urgent. It is not known whether copayments assessed on this population will discourage ED visits for non-urgent conditions.

Research question: Does a copay for non-urgent ED use discourage Healthy Michigan Plan enrollees from using the ED for non-urgent visits?

Methods: We use Medicaid administrative claims data for enrollees in Michigan’s Medicaid expansion program who had at least 18 months of continuous enrollment, and who enrolled in the program between its inception in April 2014 and March 2015. We classify ED visits into low-medium-high severity using administrative codes, and separately into copay-eligible/copay-exempt using state algorithms. Using a time series design, we compare ED utilization for urgent visits and non-urgent visits between the first six months of an individual’s enrollment, in which no copays were assessed, with subsequent utilization. We examine use of the ED for low, medium and high severity visits. We also analyze total spending in the ED as well as spending for each type of visit. We control for age, gender, income level and region of the state.

Results: This project is part of a required independent evaluation related to Michigan’s 1115 waiver for the Medicaid expansion demonstration. Per terms of the evaluation agreement, results are reviewed by officials at the Michigan Department of Health and Human Services before external release.

Conclusions: Conclusions will be based on data and available after results are reviewed by the state in early 2018.