Trends in Long-term Survival After Acute Ischemic Stroke Among Medicare Beneficiaries: Population-based Cohort Study

INTRODUCTION: Few studies have examined temporal trends in long-term survival after acute ischemic stroke (AIS) across demographic groups. This study examined long-term survival trends among Medicare fee-for-service (FFS) beneficiaries hospitalized with AIS during 2000-2019, with follow-up through 2024. METHODS: This study analyzed data from 2,118,429 FFS beneficiaries aged ≥66 years hospitalized with incident AIS between January 1, 2000, and December 31, 2019. The cohort was categorized into four time periods: 2000-2004, 2005-2009, 2010-2014, and 2015-2019. Adjusted 1- and 5-year survival were estimated using Cox proportional hazards model across age, sex, race and ethnicity and Charlson Comorbidity Index (CCI) categories. Trends were assessed using average annual percent change (AAPC) via Joinpoint regression. RESULTS: From 2000-2004 to 2015-2019, adjusted 1- and 5-year stroke survival increased significantly from 80.3% to 83.4% (AAPC: 0.22%), and from 46.1% to 52.2% (AAPC: 0.75%), respectively. Survival increased across all age groups, both sexes, all race and ethnicity categories, and CCI categories. Beneficiaries aged ≥75 years showed greater annual increases in 1-year survival than those aged 66-74 years. Black beneficiaries had greater increases in 1-year survival than White beneficiaries, although their survival remained lower. Beneficiaries with more comorbidities (CCI ≥2) had greater improvements compared to those without comorbidities, though they maintained lower survival. CONCLUSIONS: Long-term survival after AIS improved significantly for Medicare FFS beneficiaries over time. However, the varying degrees of improvement and the persistent differences across demographic groups highlight the need for focused and tailored strategies to reduce differences in stroke outcomes.