This study uses a national multi-payer claims database to test for differences in potentially inappropriate emergency department (ED) visits and ambulatory care sensitive (ACS) admissions in fee-for-service (FFS) Medicare and Medicare Advantage (MA) plans. Rates of ACS admissions for MA enrollees were approximately one third those of FFS beneficiaries, controlling for covariates, which included the beneficiary's health status as represented by their risk score. This study then compared FFS and MA beneficiaries when they moved from one type of health plan to another. Again, controlling for covariates, potentially inappropriate ED visits and ACS admissions remained at their low baseline values for FFS beneficiaries who switched from FFS Medicare to MA plans, but rose for MA enrollees switching to FFS Medicare.
Keywords: ACS admissions; ED visits; Medicare; Medicare Advantage; inappropriate utilization.