Global burden and trends of subarachnoid hemorrhage in women aged 55 years and older: A repeated cross-sectional analysis of the GBD 2021 study

Subarachnoid hemorrhage (SAH) is a highly fatal stroke subtype with high mortality and disability. Women aged 55 years and older, approximating the postmenopausal population, carry a substantial share of this burden, yet global estimates for this group remain poorly defined. In this repeated cross-sectional analysis of Global Burden of Disease 2021 data, we examined incidence, prevalence, mortality, and disability-adjusted life years (DALYs) among women aged 55 years and older in 204 countries and territories from 1990 to 2021. Rates were directly age-standardized to the World Health Organization World Standard Population, and trends were summarized using the estimated annual percentage change from log-linear regression. We decomposed demographic and epidemiological drivers. Socioeconomic inequality was assessed with the concentration index and the slope index of inequality against the sociodemographic index (SDI). Between 1990 and 2021, the absolute number of incident and prevalent cases increased sharply, whereas deaths and DALYs declined slightly, even as age-standardized rates fell (all 4 rate trends declined significantly; estimated annual percentage change for the incidence rate = -1.65, 95% confidence interval = -1.77 to -1.52). The burden increased sharply after age 70. East Asia, particularly China, saw the sharpest declines in incidence and mortality rates, whereas India, Indonesia, and sub-Saharan Africa saw notable increases in absolute case numbers. Demographic shifts, mainly population aging and growth, drove the rising burden. Improvement in high-SDI regions explained little. After age standardization, none of the 4 rates was clearly correlated with SDI. Inequality analyses showed absolute gaps that narrowed for deaths and DALYs but widened slightly for prevalence, with prevalent cases concentrated in higher-SDI countries and deaths and DALYs in lower-SDI countries. The absolute burden of SAH in women aged 55 years and older is increasing because of population aging and socioeconomic disparities. Priorities should include targeted blood pressure screening and control for this age group in primary care, standardized emergency neurosurgical referral pathways, and expanded access to noninvasive neurovascular imaging in low and low-middle SDI regions.