Adjusted Mortality Rates Are Lower For Medicare Advantage Than Traditional Medicare, But The Rates Converge Over Time

Abstract

Overall age-sex-Medicaid adjusted mortality rates in Medicare Advantage have been below those of Traditional Medicare for many years. They do, however, move toward mortality rates in Traditional Medicare as time after enrollment in Medicare Advantage lengthens. As a result, a common type of study design that compares new Medicare Advantage beneficiaries immediately before and after enrollment in Medicare Advantage with beneficiaries who remain in Traditional Medicare to estimate causal effects of Medicare Advantage on utilization and outcomes is flawed.