Featured ArticlePopulation-based stroke and dementia incidence trends: Age and sex variations

- First study of stroke and dementia incidence trends across demographic subgroups.
- Minimal sex variation in stroke and dementia incidence trends across age strata.
- Stroke and dementia incidence are concomitantly declining in those aged 80+.
- No significant temporal changes in mean age of diagnosis of stroke and dementia.
- An integrated system of stroke and dementia prevention seems desirable.

IntroductionWe discovered a concomitant decline in stroke and dementia incidence rates at a whole population level in Ontario, Canada. This study explores these trends within demographic subgroups.MethodsWe analyzed administrative data sources using validated algorithms to calculate stroke and dementia incidence rates from 2002 to 2013.ResultsFor more than 12 years, stroke incidence remained unchanged among those aged 20 to 49 years and decreased for those aged 50 to 64, 65 to 79, and 80+ years by 22.7%, 36.9%, and 37.9%, respectively. Dementia incidence increased by 17.3% and 23.5% in those aged 20 to 49 and 50 to 64 years, respectively, remained unchanged in those aged 65 to 79 years, and decreased by 15.4% in those aged 80+ years.DiscussionThe concomitant decline in stroke and dementia incidence rates may depict how successful stroke prevention has targeted shared risk factors of both conditions, especially at advanced ages where such risk factors are highly prevalent. We lend support for the development of an integrated system of stroke and dementia prevention.