Sex Differences in Causes of Death After Stroke: Evidence from a National, Prospective Registry

Abstract

Background: We examined sex differences in cause of death and cause-specific excess mortality after stroke. Materials and Methods: First-ever strokes (2010–2013; 35 hospitals) participating in the Australian Stroke Clinical Registry were linked to national death registrations and other administrative datasets. One-year cause-specific mortality was categorized as stroke, ischemic heart disease, other cardiovascular disease (CVD; e.g., hypertension), cancer, and other. Specific hazard ratios (sHRs) of death for women compared to men were estimated using competing risk models, with adjustment for factors differing by sex (e.g., age and stroke severity). Age- and sex-specific mortality rates expected in the general population were derived from national data. Standardized mortality ratios (SMRs; observed/expected deaths) were estimated for cause-specific mortality by sex after age standardization. Results: Among 9,441 cases (46% women), women were 7 years older than men, had more severe strokes, and received similar patterns of suboptimal secondary prevention medications at discharge. Women had greater mortality associated with stroke (sHRunadjusted 1.65) and other CVD (sHRunadjusted 1.65), which was related to age and stroke severity rather than other factors. Compared to population norms, those surviving to 30 days had eight-fold increased mortality from stroke (primary/recurrent) events irrespective of sex (SMRage-standardised women 8.8; men 8.3). Excess mortality from other CVD was greater in women (SMRage-standardised 3.6 vs. men 2.8; p = 0.026). Conclusions: Cause-specific mortality after first-ever stroke differs by sex. The greater death rate attributed to stroke/other CVD in women was mostly explained by age and stroke severity. Greater implementation of secondary stroke prevention is relevant to both sexes.