Temporal Trends and Racial Disparities in Long-Term Survival After Stroke

Abstract

Background and objectives: Few studies have examined trends and disparities in long-term outcome after stroke in a representative US population. We used a population-based stroke study in the Greater Cincinnati Northern Kentucky region to examine trends and racial disparities in poststroke 5-year mortality. Methods: All patients with acute ischemic strokes (AISs) and intracerebral hemorrhages (ICHs) among residents ≥20 years old were ascertained using ICD codes and physician-adjudicated using a consistent case definition during 5 periods: July 1993-June 1994 and calendar years 1999, 2005, 2010, and 2015. Race was obtained from the medical record; only those identified as White or Black were included. Premorbid functional status was assessed using the modified Rankin Scale, with a score of 0-1 being considered "good." Mortality was assessed with the National Death Index. Trends and racial disparities for each subtype were analyzed with logistic regression. Results: We identified 8,428 AIS cases (19.3% Black, 56.3% female, median age 72) and 1,501 ICH cases (23.5% Black, 54.8% female, median age 72). Among patients with AIS, 5-year mortality improved after adjustment for age, race, and sex (53% in 1993/94 to 48.3% in 2015, overall effect of study year p = 0.009). The absolute decline in 5-year mortality in patients with AIS was larger than what would be expected in the general population (5.1% vs 2.8%). Black individuals were at a higher risk of death after AIS (odds ratio [OR] 1.23, 95% CI 1.08-1.39) even after adjustment for age and sex, and this effect was consistent across study years. When premorbid functional status and comorbidities were included in the model, the primary effect of Black race was attenuated but race interacted with sex and premorbid functional status. Among male patients with a good baseline functional status, Black race remained associated with 5-year mortality (OR 1.4, 95% CI 1.1-1.7, p = 0.002). There were no changes in 5-year mortality after ICH over time (64.4% in 1993/94 to 69.2% in 2015, overall effect of study year p = 0.32). Discussion: Long-term survival improved after AIS but not after ICH. Black individuals, particularly Black male patients with good premorbid function, have a higher mortality after AIS, and this disparity did not change over time.