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Oxford University Press - PMC COVID-19 Collection logoLink to Oxford University Press - PMC COVID-19 Collection
. 2020 Dec 16:jiaa767. doi: 10.1093/infdis/jiaa767

Natural history of COVID-19: Risk factors for hospitalizations and deaths among >26 million U.S. Medicare beneficiaries

Hector S Izurieta 1,, David J Graham 2, Yixin Jiao 3,, Mao Hu 3, Yun Lu 1, Yue Wu 3, Yoganand Chillarige 3, Michael Wernecke 3, Mikhail Menis 1, Douglas Pratt 1, Jeffrey Kelman 4, Richard Forshee 1
PMCID: PMC7799044  PMID: 33325510

Abstract

Background

Evaluate risk factors for severe COVID-19 outcomes among Medicare beneficiaries during the pandemic’s early phase.

Methods

Retrospective cohort study covering Medicare fee-for-service (FFS) beneficiaries. We separated out elderly residents in nursing homes (NH) and those with end-stage renal disease (ESRD) from the primary study population of individuals ages ≥65. Outcomes included COVID-19 hospital encounters and COVID-19-associated deaths. We estimated adjusted odds ratios (ORs) using logistic regression.

Results

We analyzed 25,333,329 elderly non-NH non-ESRD beneficiaries, 653,966 elderly NH residents, and 292,302 ESRD patients. COVID-related death rates (per 10,000) were much higher among elderly NH residents (275.7) and ESRD patients (60.8) than the primary study population (5.0). Regression-adjusted clinical predictors of death among the primary population included immunocompromised status (OR: 1.43), frailty index conditions such as cognitive impairment (3.16) as well as other comorbidities including congestive heart failure (1.30). Demographics-related risk factors included male sex (1.77), older age (OR: 3.09 for 80-year-old vs. 65-year-old), Medicaid dual-eligibility status (2.17) and racial/ethnic minority. Compared to Whites, ORs were higher for Blacks (2.47), Hispanics (3.11), and Native Americans (5.82). Results for COVID-19 hospital encounters were consistent.

Conclusions

Frailty, comorbidities, and race/ethnicity were strong risk factors of COVID-19 hospitalization and death among the U.S. elderly.

Keywords: COVID-19, risk factors, disease severity, epidemics


Articles from The Journal of Infectious Diseases are provided here courtesy of Oxford University Press

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