Sex-related time-dependent variations in post-stroke survival--evidence of a female stroke survival advantage.
BACKGROUND
Women live longer than men, yet most studies show that gender has no influence on survival after stroke.


METHODS
A registry was started in 2001, with the aim of registering all hospitalized stroke patients in Denmark, and it now holds 39,484 patients of which 48% are female. We studied the influence of gender on post-stroke mortality, from the time of admission through the subsequent years until death or censoring (mean follow-up time: 538 days). All patients underwent an evaluation including stroke severity, computed tomography and cardiovascular risk factors. Independent predictors of death were identified by means of a survival model based on 22,222 individuals with a complete data set.


RESULTS
Females were older and had severer stroke. Interestingly, the risk of death between genders was time dependent. The female/male stroke mortality rate favoured women from the first day of stroke and remained so during the first month suggesting a female survival advantage. Throughout the second month the rate reversed in favour of men suggesting that women in that period are paying a 'toll' for their initial survival advantage. Hereafter, the rate steadily decreased, and after 4 months women continued to have the same low risk as in the first week.


CONCLUSIONS
Our study suggests a female superiority in stroke survival competence.
Olsen
Tom Skyhøj
TS
Stroke Unit, Hvidovre University Hospital, Hvidovre, Denmark. Tom.Skyhoej.Olsen@hvh.regionh.dk
Dehlendorff
Christian
C
Andersen
Klaus Kaae
KK
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D002543:Cerebral Hemorrhage / Q000401:mortality; D003718:Denmark; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008432:Mathematical Computing; D008875:Middle Aged; D010343:Patient Admission / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D012008:Recurrence; D012042:Registries; D012307:Risk Factors; D012744:Sex Ratio; D020521:Stroke / Q000401:mortality*; D016019:Survival Analysis