OBJECTIVE: The objective of this study was to evaluate the relationship between self reported cost-related nonadherence to medications and emergency department utilization among a population of Medicare beneficiaries. We hypothesized that persons who reported cost-related medication nonadherence (CRN) would have higher emergency department (ED) use. METHODS: We conducted a retrospective cohort study of continuously enrolled Medicare beneficiaries from in 2006 and 2007. We used multivariate logistic regression to evaluate the relationship between ED use and CRN. Our principal dependent variable was any emergency department visit within a 364-day period after the initial interview assessing CRN. Our principal independent variables were two variables to denote CRN: mild CRN, defined as a reduction in medication dose or delay in getting medications because of cost, and severe CRN, defined as a medication not being filled at all due to cost. RESULTS: Our sample consisted of 7177 Medicare Cost Beneficiary Survey (MCBS) MCBS respondents. Approximately 7.5 percent of these respondents reported mild CRN only (n=541) and another 8.2 percent reported severe CRN (n=581). Disabled Medicare beneficiaries with severe CRN were more likely to have at least one ED visit (1.53, 95% CI 1.03–2.26) as compared to both disabled Medicare beneficiaries without CRN and elderly Medicare beneficiaries in all CRN categories. CONCLUSIONS: Our results show an association between severe CRN and emergency department use. Disabled beneficiaries under age 65 who report severe CRN were more likely to have at least one emergency department visit, even when adjusting for other factors that impact utilization
