Sex differences in ischaemic stroke care and outcomes. A longitudinal Scottish national data-linkage study

Abstract Background and Purpose Stroke is characterised by important sex differences. Men have a higher incidence of stroke, while women have worse functional and mortality outcomes after acute ischaemic stroke (AIS). This may be driven by sex differences in acute care and long-term secondary prevention. We aimed to describe these sex differences in a Scottish National Cohort. Methods All consecutive AIS admissions aged 45-80 years between 2010-2016 in Scotland were extracted and linked with prescription and death certificate data. Poisson regressions analysed in-hospital mortality). Cox and Royston-Parmar regressions analysed the long-term outcomes (in-hospital mortality, long-term all-cause and cardiovascular mortality, incident cardiovascular events and recurrent AIS, secondary prevention). Median follow-up was 8.3 years. Long-term outcomes were also compared between AIS patients and age-/sex-matched ‘healthy’ controls. Models were sequentially adjusted for age, demographics, comorbidities and secondary prevention. Results 21,270 AIS patients and 36,789 matched controls were included. 42.6% were women. Women were older (median age 71 vs 68 years) and had more comorbidities compared to men. Women had higher unadjusted risk of in-hospital (risk ratio (95% confidence interval) - 1.33 (1.22-1.45)) and long-term mortality (1.06 (1.02-1.10)). Adjustment for age, demographics and comorbidities revealed higher mortality risk for women in hospital (1.26 (1.15-1.37)), but lower in the long term (0.95 (0.92-0.99)). Further adjustment for medications revealed 10% lower risk of long-term mortality for women (0.90 (0.86-0.93)). Women were 5% less likely to be on secondary prevention after discharge (0.95 (0.94-0.97)). The female advantage in long-term outcomes was more pronounced amongst the matched controls compared to the AIS cases. Conclusions Women had worse stroke outcomes than men, which were partly explained by age and comorbidity burden. They also were less likely to be prescribed optimal secondary prevention, which may have resulted in preventable adverse outcomes in the long-term.