Trends in 1-Year Recurrent Ischemic Stroke in the US Medicare Fee-for-Service Population.

Background: There have been important advances in secondary stroke prevention and a focus on healthcare delivery over the past decades. Yet, data on US trends in recurrent stroke are limited. We examined national and regional patterns in 1-year recurrence among Medicare beneficiaries hospitalized for ischemic stroke from 2001 to 2017.

Methods: This cohort study included all fee-for-service Medicare beneficiaries aged ≥65 years who were discharged alive with a principal diagnosis of ischemic stroke from 2001 to 2017. Follow-up was up to 1 year through 2018. Cox models were used to assess temporal trends in 1-year recurrent ischemic stroke, adjusting for demographic and clinical characteristics. We mapped recurrence rates and identified persistently high-recurrence counties as those with rates in the highest sextile for stroke recurrence in ≥5 of the following periods: 2001-2003, 2004-2006, 2007-2009, 2010-2012, 2013-2015, and 2016-2017.

Results: There were 3 638 346 unique beneficiaries discharged with stroke (mean age 79.0±8.1 years, 55.2% women, 85.3% White). The national 1-year recurrent stroke rate decreased from 11.3% in 2001-2003 to 7.6% in 2016-2017 (relative reduction, 33.5% [95% CI, 32.5%-34.5%]). There was a 2.3% (95% CI, 2.2%-2.4%) adjusted annual decrease in recurrence from 2001 to 2017 that included reductions in all age, sex, and race subgroups. County-level recurrence rates ranged from 5.5% to 14.0% in 2001-2003 and from 0.2% to 8.9% in 2016-2017. There were 76 counties, concentrated in the South-Central United States, that had the highest recurrence throughout the study. These counties had populations with a higher proportion of Black residents and uninsured adults, greater wealth inequity, poorer general health, and reduced preventive testing rates as compared with other counties.

Conclusions: Recurrent ischemic strokes decreased over time overall and across demographic subgroups; however, there were geographic areas with persistently higher recurrence rates. These findings can inform secondary prevention intervention opportunities for high-risk populations and communities.