Risk of Recurrent Stroke and Mortality among Black and White Patients with Poststroke Depression

BACKGROUND: Poststroke depression (PSD) is a treatable and common complication of stroke that is underdiagnosed and undertreated in minority populations. We compared outcomes of Black and White patients with PSD in the United States to assess whether race is independently associated with the risk of recurrent stroke and mortality. METHODS: We used deidentified Medicare data from inpatient, outpatient, and subacute nursing facilities for Black and White US patients from January 1, 2016, to December 31, 2019, to perform this retrospective cohort analysis. International Classification of Diseases, Tenth Revision codes were used to identify patients diagnosed with depression within 6 months of index stroke with no depression diagnosis 1-year preceding index stroke. We performed an unadjusted Kaplan-Meier analysis of the cumulative risk of recurrent stroke up to 3 years after index acute ischemic stroke admission and all-cause mortality following acute ischemic stroke stratified by Black and White race. We performed adjusted and reduced Cox regression to calculate hazard ratios for the main predictor of race (Black versus White), for recurrent stroke and all-cause mortality, adjusting for sociodemographic characteristics, comorbidities, characteristics of the hospitalization, and acute stroke interventions. RESULTS: Of 474 770 Medicare patients admitted with acute index stroke, 443 486 were categorized as either Black or White race and 35 604 fulfilled our criteria for PSD. Within the PSD cohort, 25 451 (71.5%) had no death or recurrent stroke within 6 months and 5592 (15.7%) had no death or readmission of any cause within 6 months. Black patients with PSD had a persistently elevated cumulative risk of recurrent stroke compared with White patients with PSD up to 3 years following acute ischemic stroke (log-rank P=0.0011). In our reduced multivariable model, Black patients had a 19.8% (hazard ratio, 1.198 [95% CI, 1.022-1.405]; P=0.0259) greater risk of recurrent stroke than White patients. The unadjusted cumulative risk of all-cause mortality was higher in this cohort of older White patients with PSD compared with Black patients; however, this difference disappeared with adjustment for age and other cofactors. CONCLUSIONS: Black patients with PSD face a persistently elevated risk of recurrent stroke compared with White patients but a similar risk of all-cause mortality. Our findings support that black race is an independent predictor of recurrent stroke in patients with PSD and highlight the need to address social determinants of health and systemic racism that impact poststroke outcomes among racial minorities.