Sex-specific temporal trends in in-hospital mortality after stroke among middle-age individuals in the United States

Abstract

Background and purpose: Recent studies have revealed an increase in stroke prevalence among middle-aged women in the United States. To determine whether this is due to improved survival, we assessed temporal trends in sex-specific in-hospital mortality after stroke.

Methods: Individuals aged 35 to 64 years hospitalized in 1997 to 2006 with a primary discharge diagnosis of stroke (N=2 537 097) in the United States were identified by the Nationwide Inpatient Sample. Temporal trends in sex-specific mortality after stroke and sex differences in mortality were assessed, before and after controlling for covariates.

Results: From 1997 to 2006, poststroke mortality decreased in both men (6.06% to 5.15%) and women (6.02% to 4.88%) aged 35 to 64 years. Unadjusted analysis revealed that women aged 35 to 44 years (odds ratio=0.89; 95% CI, 0.83 to 0.95) and 45 to 54 years (odds ratio=0.93; 95% CI, 0.89 to 0.97) had lower mortality compared with men, whereas women aged 55 to 64 years had similar mortality compared with men. After adjustment for covariates, stroke type accounted for the better survival in women aged 35 to 44 years. After adjustment for covariates, women aged 45 to 54 years persistently had better survival than did men. Women aged 55 to 64 years had better survival than did men, once race and insurance type were accounted for.

Conclusions: This study revealed a decline in stroke mortality rates from 1997 to 2006 among individuals aged 35 to 64 years. Better survival among women compared with men aged 35 to 54 years may partially explain the sex disparity in stroke prevalence.