Ethnic and socioeconomic inequalities in stroke risk factors and primary prevention over three decades: the South London Stroke Register cohort study 1995-2024

ABSTRACT Objectives To investigate long-term trends in ethnic and socioeconomic inequalities in pre-stroke risk factors and treatments. Design population-based cohort study Setting geographically defined area of London, UK, 1995-2024 Participants 8,515 adults with first stroke, stratified by self-reported ethnicity (62.4% White [N=5,255], 15.5% Black Caribbean [N=1,303], 13.3% Black African [N=1,122]), occupation (60.7% routine/manual occupations [N=3,964]), education (44.6% lower education [N=1,929]), and 10-year cohorts Outcome measures pre-stroke vascular risk factor diagnoses and prescribed treatments Results Mean age at stroke was 59.6 years in Black Africans, 68.1 in Black Caribbeans, and 71.8 in White participants. 12.0% of Black Africans’ strokes occurred without pre-stroke risk factor diagnosis (White participants: 6.3%). Compared to their counterparts, Black participants and those with routine/manual occupations or lower education had higher rates of hypertension (adjusted prevalence ratio: Black Caribbean 1.29 [95%CI:1.24 to 1.34], Black African 1.47 [1.40 to 1.53], manual/routine 1.09 [1.05 to 1.13], lower education 1.06 [1.02 to 1.11]), and diabetes (Black Caribbean 2.23 [2.04 to 2.43], Black African 1.92 [1.73 to 2.13], manual/routine 1.23 [1.13 to 1.34], lower education 1.21 [1.09 to 1.37]), but lower rates of atrial fibrillation (Black Caribbean 0.57 [0.48 to 0.68], Black African 0.66 [0.54 to 0.82], lower education 0.78 [0.68 to 0.91]). Ethnic and socioeconomic inequalities in diabetes and hypertension widened over time but narrowed for atrial fibrillation. 36% of strokes occurred in people with at least one diagnosed, but untreated risk factor throughout the study period. Treatment rates were not associated with occupation or education, but Black participants had higher treatment rates for hypertension and diabetes. Adjusting for occupation or education had negligible impact on associations between ethnicity and risk factor diagnosis or treatment. Conclusion Prevalence of pre-stroke hypertension and diabetes is higher and rising faster in ethnic minority and lower socioeconomic groups. Together with Black people’s younger stroke age and higher likelihood of having stroke without any prior risk factor diagnosis, these findings indicate that targeted and earlier primary prevention efforts are needed. Registration This study is registered at ClinicalTrials.gov (Identifier: NCT05298436 ).