Introduction: Blacks have a higher incidence of stroke compared with whites. Most stroke survivors in the United States are 65 years and older but few data are available on racial differences in recurrent stroke risk in this age group.
Methods: We conducted a retrospective cohort of Medicare beneficiaries in the 5% sample from 1999-2013 to compare 1-year recurrent stroke risk in older black and white Americans following hospitalization for ischemic stroke. We studied beneficiaries with Medicare fee-for-service coverage for 182 days before the index stroke hospitalization with no claims for stroke-related events. Patients were divided into two age groups (66-74, 75 years and above) and stratified into 3 calendar periods (1999-2001, 2002-2006, 2007-2013) allowing for implementation of secondary stroke prevention trial findings (PROGRESS, 2001; SPARCL, 2006). Hazard ratios for recurrent ischemic stroke comparing blacks to whites were calculated with adjustment for demographics, risk factors, and the competing risk of death.
Results: Of 128,789 ischemic stroke patients (mean age 80 years [SD 8], 11.1% black, 60.4% male), 7.8% of whites and 11.0% of blacks had a recurrent ischemic stroke overall (Table 1). For each time period, blacks had a higher risk of recurrent stroke compared with whites (Figure 1). This disparity increased over time among patients age 66-74 years (p=0.038) but no trend was present for those 75 years and above (p=0.301).
Conclusion: The risk of stroke recurrence among older Americans hospitalized for ischemic stroke is higher for blacks than whites, regardless of age group.