Age- and Sex-Specific Risk Profiles and In-Hospital Mortality in 13,932 Spanish Stroke Patients

Background: In-hospital stroke death rate is an important sanitary issue. Despite advances in the acute phase management of stroke patients, mortality and disability rates remain high. In aging populations and with different mortality between the sexes in general, the study of sex- and age-related differences becomes increasingly relevant for optimization of post-acute clinical care of stroke patients.

Methods: We designed a cohort follow-up study with 13,932 consecutive ischemic stroke (IS) patients from 19 Spanish hospitals. Data was obtained from the Spanish Stroke Registry; transient ischemic attacks and ages <18 years were excluded. Patients were organised by age group and sex. We compared female and male patient cohorts within and across age groups univariately and used multivariable logistic regression to adjust for confounders in differential in-hospital mortality.

Results: The median (percentiles 2.5 and 97.5%) age was 78 (41-92) years old for women and 71 (41-92) for men. IS women were more likely to be older, to exhibit cardio-embolic aetiology, and less likely to have been admitted to a stroke unit or to have had a stroke code activated. Both pre-stroke modified Rankin Scale and National Institute of Health Stroke Scale (NIHSS) scores at admission increased significantly with age and were higher in women than those in men. Differences in distributions of common risk factors for IS and of in-hospital outcomes between women and men actually changed with patient's age. It is to be noted here that although there were no statistically significant differences (p > 0.05) between the sexes within any age group, in-hospital mortality appeared significantly higher in women than that in men when analysed overall, due to confounding. Death was more closely related to stroke in women than in men and occurred earlier. Although there were some age-specific sex differences between the predictors for in-hospital mortality, stroke severity measured by NIHSS was the main predictor of in-hospital mortality for both sexes. Topographic classifications - partial anterior circulatory infarct and total anterior circulatory infarct - were significant prognostic factors for men aged <60 years and for those in the 60-69 years range respectively.

Conclusion: Although most of our findings were consistent with previous studies, it is important to take into account and highlight differences in in-hospital mortality between the sex and age group. Not to account for age-related differences between the sexes can give false results that may mislead management decisions. As most deaths in women were related to stroke, it is important to improve their early management, stroke code activation, access to stroke units and/or revascularisation therapies, especially in the older age groups.