Patterns of national emergency department utilization by fee-for-service Medicare beneficiaries with dementia

Background: Individuals with Alzheimer's disease and related dementias (ADRD) often face high acute care clinical utilization and costs with unclear benefits in survival or quality of life. The emergency department (ED) is frequently the site of pivotal decisions in these acute care episodes. This study uses national Medicare data to explore this population's ED utilization. Methods: Retrospective cohort study of persons aged >= 66 years enrolled in traditional Medicare with a Chronic Condition Warehouse diagnosis of dementia. Primary 1-year outcome measures included ED visits with and without hospitalization, ED visits per 100 days alive, and health-care costs. A multivariate random effects regression model (clustered by county of residence), adjusted for sociodemographics and comorbidities, examined how place of care on January 1, 2018, was associated with subsequent ED utilization. Results: In 2018, 2,680,006 ADRD traditional Medicare patients (mean age 82.9, 64.2% female, 9.4% Black, 6.2% Hispanic) experienced a total of 3,234,767 ED visits. Over half (52.2%) of the cohort experienced one ED visit, 15.5% experienced three or more, and 37.1% of ED visits resulted in hospitalization. Compared with ADRD patients residing at home without services, the marginal difference in ED visits per 100 days alive varied by location of care. Highest differences were observed for those with hospitalizations (0.48 visits per 100 days alive, 95% confidence interval [CI] 0.47-0.49), skilled nursing facility (rehab/skilled nursing facility [SNF]) stays (0.27, 95% CI 0.27-0.28), home health stays (0.25, 95% CI 0.25-0.26), or observation stays (0.82, 95% CI 0.77-0.87). Similar patterns were observed with ED use without hospitalization and health-care costs. Conclusions: Persons with ADRD frequently use the ED-particularly those with recent hospitalizations, rehab/SNF stays, or home health use-and may benefit from targeted interventions during or before the ED encounters to reduce avoidable utilization and ensure goal-concordant care.