Abstract WMP52: Age, Sex and Regional Differences in Recent Stroke Incidence Trends Among Young Adults

Background: In the US, one third of strokes occur among younger adults (< 65 years). While stroke incidence among elderly has declined, trends in younger adults by age, sex and region are unknown. We report recent trends in stroke incidence among commercially-insured young adults aged 20 - 64. Methods: Stroke incidence was estimated using 2011 - 2017 IBM MarketScan® Commercial Database stratified by age (20 - 34, 35 - 44, 45 - 54, 55 - 64), sex, and US Census region and was extrapolated to the US population using census data. Stroke cases were identified based on a primary diagnosis of either ischemic stroke (IS) or intracerebral hemorrhage (ICH) or subarachnoid hemorrhage (SAH) using validated ICD-9 / 10 codes. We report incidence rates (IR) per 100,000 person-years, 95% confidence intervals and proportional change in IR between 2011 and 2017. Results: We identified 115,276 stroke admissions resulting in 172 million person-years. The overall stroke IR increased by 7% from 60.0 to 64.2 per 100,000 person-years between 2011 and 2017. The increase was greater among males as compared to females (9.8% vs 3.3%) and across both sexes the largest increase was observed for age category of 35 - 44 years (Table 1). Age-specific IR increased in all age categories except 20 - 34. Across US regions, the South showed the highest IR increase (10.0%) (Figure 1). IR for IS and ICH increased while a decrease in SAH IR was observed. The IR for IS was higher for males vs females (12.7% vs 5.4%), whereas it was higher for females vs males for ICH (14.5% vs 3.6%). Conclusions: Our analyses indicate an overall increase in stroke incidence for commercially-insured younger adults during a contemporary time period. Males between the ages of 35 - 44 have experienced the greatest increase in stroke incidence. Furthermore, the Southern US continues to experience highest increases in stroke incidence and there are gender differences in IR for stroke subtypes. Targeted strategies for stroke prevention may be warranted.