Mortality Rates Among Medicare Enrollees With Alzheimer Disease and Related Dementias During the Early Phase of the COVID-19 Pandemic

Regional Measures of Covid-19 Cases and Mortality

Last Updated February 2022

Source Centers for Medicare & Medicaid Services (CMS)

The COVID-19 pandemic fundamentally altered the delivery of healthcare in the United States. The association between these COVID-19-related changes and vulnerable patient outcomes, such as those with Alzheimer’s Disease and Related Dementias (ADRD), is not yet well understood. For this reason, we determined the association between regional rates of COVID-19 infection and excess mortality among individuals with ADRD.

The paper "Trends in Mortality Rates Among Medicare Enrollees With Alzheimer Disease and Related Dementias Before and During the Early Phase of the COVID-19 Pandemic", published February 2023 in JAMA Neurology, can be found here. On this page, we include HRR-level regional measures used in the analysis and will include computer code (SAS for the VRDC data set plus STATA code for subsequent analysis).

We created a retrospective cross-sectional analysis. Excess mortality was calculated by comparing mortality rates in 2020 to rates in 2019 for specific, pre-determined groups. Setting: 100% fee-for-service Medicare Parts A and B between January 1, 2019 and December 31, 2020. Using fee-for-service Medicare enrollees aged 65 and older, we compared age/sex adjusted mortality rates from 26.7 million enrollees in 2020 and 26.9 million enrollees in 2019 for 4 prespecified cohorts: 1) ADRD; 2) non-ADRD; 3) ADRD in nursing homes; 4) non- ADRD in nursing homes. The exposure was COVID-19 infection rates by hospital referral region (HRR) between January and December 2020. Main Outcomes and measures were Mortality rate in March-December 2020 compared to March-December 2019.

The sample was 26.9 million Medicare enrollees in 2019 and 26.7 million enrollees in 2020. In this cross-sectional study of Medicare enrollees 65 years of age and older, we found excess mortality associated with the COVID-19 pandemic among older adults with ADRD, especially for Asian, Black, and Hispanic populations and people living nursing homes, even in areas with low COVID-19 prevalence.