Sex differences in stroke incidence, prevalence, mortality and disability-adjusted life years: Results from the Global Burden of Disease study 2013

Background

Accurate information on stroke burden in men and women is important for evidence-based healthcare planning and resource allocation. Previously, limited research suggested that the absolute number of deaths from stroke in women was greater than in men, but the incidence and mortality rates were greater in men. However, sex differences in various metrics of stroke burden on a global scale have not been a subject of comprehensive and comparable assessment for most regions of the world, nor have sex differences in stroke burden been examined for trends over time.

Methods

Stroke incidence, prevalence, mortality, disability-adjusted life years (DALYs) and healthy years lost due to disability were estimated as part of the Global Burden of Disease (GBD) 2013 study. Data inputs included all available information on stroke incidence, prevalence, and death and case fatality rates. Analysis was performed separately by sex and 5-year age categories for 188 countries. Statistical models were employed to produce globally comprehensive results over time. All rates were age-standardized to a global population, and 95% uncertainty intervals (UIs) were computed.

Findings

In 2013, global ischemic stroke (IS) and hemorrhagic stroke (HS) incidence (per 100,000) in men (IS 132.77 (95% UI 125.34–142.77); HS 64.89 (95% UI 59.82–68.85)) exceeded those of women (IS 98.85 (95% UI 92.11–106.62); HS 45.48 (95% UI 42.43–48.53)). IS incidence rates were lower in 2013 compared with 1990 rates for both sexes (1990 male IS incidence 147.40 (95% UI 137.87–157.66); 1990 female IS incidence 113.31 (95% UI 103.52–123.40)), but the only significant change in IS incidence was among women. Changes in global HS incidence were not statistically significant for males (1990 = 65.31 (95% UI 61.63–69.0), 2013 = 64.89 (95% UI 59.82–68.85)), but was significant for females (1990 = 64.892 (95% UI 59.82–68.85), 2013 = 45.48 (95% UI 42.427–48.53)). The number of DALYs related to IS rose from 1990 (male = 16.62 (95% UI 13.27–19.62), female = 17.53 (95% UI 14.08–20.33)) to 2013 (male = 25.22 (95% UI 20.57–29.13), female = 22.21 (95% UI 17.71–25.50)). The number of DALYs associated with HS also rose steadily and was higher than DALYs for IS at each time point (male 1990 = 29.91 (95% UI 25.66–34.54), male 2013 = 37.27 (95% UI 32.29–45.12); female 1990 = 26.05 (95% UI 21.70–30.90), female 2013 = 28.18 (95% UI 23.68–33.80)).

Interpretation

Globally, men continue to have a higher incidence of IS than women, while significant sex differences in the incidence of HS were not observed. The total health loss due to stroke as measured by DALYs was similar for men and women for both stroke subtypes in 2013, with HS higher than IS. Both IS and HS DALYs show an increasing trend for both men and women since 1990, which is statistically significant only for IS among men. Ongoing monitoring of sex differences in the burden of stroke will be needed to determine if disease rates among men and women continue to diverge. Sex disparities related to stroke will have important clinical and policy implications that can guide funding and resource allocation for national, regional, and global health programs.