Risk Factors for Persistent Frequent Emergency Department Use in Medicare Beneficiaries

Study objective We examine factors associated with persistent frequent emergency department (ED) use during a 2-year period among Medicare beneficiaries. Methods We conducted a retrospective, claims-based analysis of fee-for-service Medicare beneficiaries, using the Chronic Condition Data Warehouse's random 20% sample files. We used multinomial logistic regression models to compare frequent ED use (defined as 4 or more ED visits per year) with infrequent use (1 to 3 visits per year), non-ED use, and death in 2010 as a function of sociodemographic, primary care, clinical characteristics, and 2009 ED use. Results Approximately 1.1% of Medicare beneficiaries were persistent frequent ED users, defined as experiencing frequent ED use in 2009 and 2010 consecutively. Of the 3.3% of Medicare beneficiaries who were frequent ED users in 2009, 34.3% were frequent ED users, 19.4% were non-ED users, 39.0% were infrequent ED users, and 7.4% died in 2010. Frequent ED use in 2009 was highly associated with frequent ED use in 2010 (relative risk ratio 35.2; 95% confidence interval 34.5 to 35.8). Younger age, Medicaid status, and mental illness were also strong predictors of frequent ED use. The probability of frequent ED use in 2010 was 3.4% for the total sample, but was 19.4% for beneficiaries who were frequent users in 2009 and 49.0% for beneficiaries in the youngest age group who had mental illness, Medicaid, and frequent ED use in 2009. Conclusion Efforts to curtail frequent ED use in Medicare should focus on disabled, socially vulnerable beneficiaries.