Nationwide trends in incidence and mortality of stroke among younger and older adults in Denmark

Objective: To investigate the extent to which the incidence and mortality of a first-time stroke among younger and older adults changed from 2005 to 2018 in Denmark using nationwide registries.

Methods: We used the Danish Stroke Registry and the Danish National Patient Registry to identify patients aged 18–49 years (younger adults) and those aged 50+ years (older adults) with a first-time ischemic stroke, intracerebral hemorrhage, or subarachnoid hemorrhage. We computed age-standardized incidence rates and 30-day and one-year mortality risks separately for younger and older adults and according to smaller age groups, stroke subtype, sex, and severity (Scandinavian Stroke Scale). Average annual percentage changes (AAPC) were computed to assess temporal trends.

Results: We identified 8,680 younger adults and 105,240 older adults with an ischemic stroke or intracerebral hemorrhage. The incidence rate per 100,000 person-years of ischemic stroke (20.8 in 2005 and 21.9 in 2018, AAPC: -0...