Incidence of Long COVID Diagnoses in 3.6 Million U.S. Medicare Beneficiaries With COVID-19

Abstract

Background: Long COVID incidence and risk factors in older adults need to be better characterized to identify risk mitigation strategies. Our aim was to quantify the incidence of Long COVID in a population-based sample of older adults and to describe the association between COVID-19 vaccination and Long COVID risk.

Methods: This cohort study included Medicare fee-for-service beneficiaries ≥ 66 years diagnosed with COVID-19 between October 1, 2021, and March 31, 2023 (index date). Long COVID diagnoses were identified from Medicare Part A-B claims based on ICD-10-CM code U09.9. We measured the number of COVID-19 vaccine doses administered prior to the index date using Medicare Part B claims and pharmacy records. Kaplan-Meier estimators, Cox proportional hazards, and Fine-Grey regression models were used to estimate the 1-year cumulative incidence and relative rate of Long COVID.

Results: We identified 3 588 671 Medicare beneficiaries diagnosed with COVID-19. Overall, 3.89% of beneficiaries were diagnosed with Long COVID over 1 year. A gradient in the 1-year cumulative incidence of Long COVID was observed according to the number of prior COVID-19 vaccine doses. Beneficiaries with 4 or more COVID-19 vaccine doses had a 39% lower adjusted rate of Long COVID relative to beneficiaries without a prior dose (adjusted hazard ratio = 0.61, 95% CI = 0.60-0.62).

Conclusions: Long COVID diagnoses in Medicare claims were common in a large sample of older adults with COVID-19, and we observed a gradient in Long COVID risk across the number of prior COVID-19 vaccine doses. Promoting continued vaccination may be an effective strategy to mitigate the burden of Long COVID in older adults.

Keywords: COVID-19; COVID-19 vaccines; Long COVID; Medicare; Older Adults.