A retrospective cohort study, examining the relationship between sex and outcome after thrombolysis has suggested that female stroke patients fared worse than their male counterparts if left untreated. However, women who were treated had comparable outcomes to men who were treated.

Researchers used data on 2113 stroke patients from the Registry of Canadian Stroke Network phase 1 (June 2001-February 2002) and phase 2 (June 2002-December 2002), of which women accounted for 43.5% of the cohort.

Variables including demographics, history, clinical data, process measures, and outcome were analyzed. The primary outcomes were the Stroke Impact Scale-16 score (SIS-16) and mortality at 6 months and these were compared in thrombolysed (thrombolytic therapy with recombinant tissue plasminogen activator [tPA]) and nonthrombolysed cohorts.

The overall proportion of patients who achieved an excellent outcome (SIS-16 >75) did not differ by gender. However, the proportion of patients achieving an excellent outcome in the non-thrombolysed cohort was much greater in males, with an absolute risk difference of 11.8% (70% in men vs 58% in women; p < 0.001). A multiplicative treatment by sex interaction was evident (p = 0.054). This interaction was not present for stroke case fatality.

In an interview with Reuters, the lead researcher commented that biological reasons could explain the difference, or perhaps older women might be less likely than older men to have a surviving spouse who can assist them in their stroke recovery. In addition, post-stroke depression, which can slow recovery, is more common in women.

[Editors note: Full text not available at time of writing.]