History of COVID-19 and Overall Survival Among Medicare Beneficiaries Hospitalized with Acute Ischemic Stroke, Medicare Cohort 2020-2021

Background: COVID-19 is associated with increased risk of Acute Ischemic Stroke (AIS). The present study examined the impact of prior COVID-19 diagnoses on overall survival among older AIS patients.

Methods: We included 250,079 Medicare Fee-For-Service (FFS) beneficiaries aged ≥65 years with AIS hospitalizations from 04/01/2020 through 12/31/2021. Overall survival was defined as the time from date of AIS hospitalization to date of death, or through end of follow-up on 03/31/2023. We used a Cox proportional hazard model to examine the association between history of COVID-19 and overall survival among AIS beneficiaries, and we obtained age, sex, race/ethnicity, Social Vulnerability Index (SVI), National Institutes of Health Stroke Scale score, and comorbidity-adjusted survival estimates.

Results: Among 250,079 Medicare FFS beneficiaries with AIS, 98,327 (39.3%) died during a median of 590 days (IQR, 169-819 days) of follow-up with a total of 365,606 person-years. The 1-year adjusted overall survival was 62.0%, 67.4%, and 68.8% in beneficiaries with hospitalized COVID-19, with non-hospitalized COVID-19 and no COVID-19 respectively (p<0.001). Compared to AIS without history of COVID-19, the adjusted mortality hazard ratios were 1.30 (95% CI, 1.26-1.34) and 1.06 (95% CI, 1.03-1.10) for those with a history of hospitalized and non-hospitalized COVID-19, respectively. The patterns of overall survival by COVID-19 history were largely consistent across age groups, sex, race/ethnicity, and SVI groups.

Conclusions: A history of COVID-19 diagnoses, especially with a history of severe COVID-19, was associated with a significantly higher risk of all-cause mortality among Medicare FFS beneficiaries hospitalized with AIS.