Background—: Women are reported to have greater mortality after stroke than men, but the reasons are uncertain. We examined sex differences in mortality at 1 and 5 years after stroke and identified factors contributing to these differences. Methods and Results—: Individual participant data for incident strokes were obtained from 13 population-based incidence studies conducted in Europe, Australasia, South America, and the Caribbean between 1987 and 2013. Data on sociodemographics, stroke-related factors, prestroke health, and 1- and 5-year survival were obtained. Poisson modeling was used to estimate the mortality rate ratio (MRR) for women compared with men at 1 year (13 studies) and 5 years (8 studies) after stroke. Study-specific adjusted MRRs were pooled to create a summary estimate using random-effects meta-analysis. Overall, 16 957 participants with first-ever stroke followed up at 1 year and 13 216 followed up to 5 years were included. Crude pooled mortality was greater for women than men at 1 year (MRR 1.35; 95% confidence interval, 1.24–1.47) and 5 years (MRR 1.24; 95% confidence interval, 1.12–1.38). However, these pooled sex differences were reversed after adjustment for confounding factors (1 year MRR, 0.81; 95% confidence interval, 0.72–0.92 and 5-year MRR, 0.76; 95% confidence interval, 0.65–0.89). Confounding factors included age, prestroke functional limitations, stroke severity, and history of atrial fibrillation. Conclusions—: Greater mortality in women is mostly because of age but also stroke severity, atrial fibrillation, and prestroke functional limitations. Lower survival after stroke among the elderly is inevitable, but there may be opportunities for intervention, including better access to evidence-based care for cardiovascular and general health.

Background: Women have worse outcomes after stroke than men, and this may be partly explained by stroke severity. We examined factors contributing to sex differences in severity of acute stroke assessed by the National Institutes of Health Stroke Scale. Methods and Results: We pooled individual participant data with National Institutes of Health Stroke Scale assessment (N=6343) from 8 population‐based stroke incidence studies (1996–2014), forming part of INSTRUCT (International Stroke Outcomes Study). Information on sociodemographics, stroke‐related clinical factors, comorbidities, and pre‐stroke function were obtained. Within each study, relative risk regression using log‐binominal modeling was used to estimate the female:male relative risk ( RR ) of more severe stroke (National Institutes of Health Stroke Scale>7) stratified by stroke type (ischemic stroke and intracerebral hemorrhage). Study‐specific unadjusted and adjusted RR s, controlling for confounding variables, were pooled using random‐effects meta‐analysis. National Institutes of Health Stroke Scale data were recorded in 5326 (96%) of 5570 cases with ischemic stroke and 773 (90%) of 855 participants with intracerebral hemorrhage. The pooled unadjusted female:male RR for severe ischemic stroke was 1.35 (95% CI 1.24–1.46). The sex difference in severity was attenuated after adjustment for age, pre‐stroke dependency, and atrial fibrillation but remained statistically significant (pooled RR _adjusted 1.20, 95% CI 1.10–1.30). There was no sex difference in severity for intracerebral hemorrhage ( RR _crude 1.08, 95% CI 0.97–1.21; RR _adjusted 1.08, 95% CI 0.96–1.20). Conclusions: Although women presented with more severe ischemic stroke than men, much although not all of the difference was explained by pre‐stroke factors. Sex differences could potentially be ameliorated by strategies to improve pre‐stroke health in the elderly, the majority of whom are women. Further research on the potential biological origin of sex differences in stroke severity may also be warranted.

Background and Purpose—: Women are reported to have poorer health-related quality of life (HRQoL) after stroke than men, but the underlying reasons are uncertain. We investigated factors contributing to the sex differences. Methods—: Individual participant data on 4288 first-ever strokes (1996–2013) were obtained from 4 high-quality population-based incidence studies from Australasia and Europe. HRQoL utility scores among survivors after stroke (range from negative scores=worse than death to 1=perfect health) were calculated from 3 scales including European Quality of Life-5 Dimensions, Short-Form 6-Dimension, and Assessment of Quality of Life at 1 year (3 studies; n=1210) and 5 years (3 studies; n=1057). Quantile regression was used to estimate the median differences in HRQoL for women compared to men with adjustment for covariates. Study factors included sociodemographics, prestroke dependency, stroke-related factors (eg, stroke severity), comorbidities, and poststroke depression. Study-specific median differences were combined into pooled estimates using random-effect meta-analysis. Results—: Women had lower pooled HRQoL than men (median difference _unadjusted 1 year, −0.147; 95% CI, −0.258 to −0.036; 5 years, −0.090; 95% CI, −0.119 to −0.062). After adjustment for age, stroke severity, prestroke dependency, and depression, these pooled median differences were attenuated, more greatly at 1 year (−0.067; 95% CI, −0.111 to −0.022) than at 5 years (−0.085; 95% CI, −0.135 to −0.034). Conclusions—: Women consistently exhibited poorer HRQoL after stroke than men. This was partly attributable to women’s advanced age, more severe strokes, prestroke dependency, and poststroke depression, suggesting targets to reduce the differences. There was some evidence of residual differences in HRQoL between sexes but they were small and unlikely to be clinically significant.

Objective To examine factors contributing to the sex differences in functional outcomes and participation restriction after stroke. Methods Individual participant data on long-term functional outcome or participation restriction (i.e., handicap) were obtained from 11 stroke incidence studies (1993–2014). Multivariable log-binomial regression was used to estimate the female:male relative risk (RR) of poor functional outcome (modified Rankin Scale score >2 or Barthel Index score <20) at 1 year (10 studies, n = 4,852) and 5 years (7 studies, n = 2,226). Multivariable linear regression was used to compare the mean difference (MD) in participation restriction by use of the London Handicap Scale (range 0–100 with lower scores indicating poorer outcome) for women compared to men at 5 years (2 studies, n = 617). For each outcome, study-specific estimates adjusted for confounding factors (e.g., sociodemographics, stroke-related factors) were combined with the use of random-effects meta-analysis. Results In unadjusted analyses, women experienced worse functional outcomes after stroke than men (1 year: pooled RR_unadjusted 1.32, 95% confidence interval [CI] 1.18–1.48; 5 years: RR_unadjusted 1.31, 95% CI 1.16–1.47). However, this difference was greatly attenuated after adjustment for age, prestroke dependency, and stroke severity (1 year: RR_adjusted 1.08, 95% CI 0.97–1.20; 5 years: RR_adjusted 1.05, 95% CI 0.94–1.18). Women also had greater participation restriction than men (pooled MD_unadjusted −5.55, 95% CI −8.47 to −2.63), but this difference was again attenuated after adjustment for the aforementioned factors (MD_adjusted −2.48, 95% CI −4.99 to 0.03). Conclusions Worse outcomes after stroke among women were explained mostly by age, stroke severity, and prestroke dependency, suggesting these potential targets to improve the outcomes after stroke in women.