Introduction: It is widely accepted that stroke incidence is higher in men than women. Recent data suggest stroke incidence is decreasing over time, but it is unknown whether incidence is decreasing in women and men to the same extent.
Methods: Within our population of 1.3 million, all strokes among area residents (≥20 years old) were ascertained at all local hospitals during 7/93-6/94 and calendar years 1999, 2005 and 2010. A sampling scheme was used to ascertain out-of-hospital cases. Only first-ever strokes were included in this analysis. Sex-specific incidence rates were adjusted for age and race, standardized to the 2000 U.S. Census population, and reported per 100,000. Trends over time by sex were compared between first and last study periods; a Bonferroni correction was applied for multiple comparisons.
Results: Across all study periods, there were 7710 incident strokes (ischemic, ICH, and SAH); 57.2% (n=4412) were women, and 19.2% (n=1482) were black. Mean age for women was 71.6 (SD 15.1) vs. 67.3 (SD 14.1) for men (p<0.001). Incidence of all strokes and of ischemic strokes decreased over time in men (p<0.001, p<0.01) but not significantly in women (p=0.15, p=0.09). Incidence of all strokes and of ischemic strokes was similar between women and men in 2010 (p=0.50, p=0.31) (Table)). ICH and SAH incidence did not decrease significantly over time in women (p=0.99, p=0.70) or men (p=0.46, 0.16).
Conclusions: The decrease in stroke incidence over time appears to be driven by a decrease in incidence of ischemic stroke in men. Contrary to previous data, stroke incidence rates were similar in men and women at the end of our study period. Future research is needed to understand why the decrease in ischemic stroke incidence is more pronounced in men than in women and whether the current trend for men will be reflected in women after 2010.