Alternative Scenarios for Projected Prevalence of Stroke and Post-Stroke Dementia to 2046 in Ireland: A Model-Based Analysis

Background Understanding future population need is key for informing stroke service planning. This study aims to evaluate alternative scenarios for future trends in stroke age-specific incidence and case-fatality and estimate impact on projected stroke and post-stroke dementia prevalence in Ireland. Methods We used a probabilistic Markov model to project and track incidence and prevalence of stroke and post-stroke dementia in the Irish population aged 40-89 years to 2046. Using systematic review and observational evidence, we extrapolated trends in stroke age-specific incidence and case-fatality from 1990-2019 to 2016-2046. We defined optimistic, realistic and pessimistic scenarios, including scenarios where trends decelerated over time. Results The stable (pessimistic) scenario indicates a projected 95,278 stroke survivors in 2046 (95% uncertainty interval, UI = 91,404-99,487) (30.1 per 1000 pop), an increase of 53% from 2022 to 2046. The most optimistic scenario would involve a 3.2% increase from 2022 to 2046, to a projected 61,000 survivors. More realistic scenarios based on lower rates of incidence/case-fatality decline, or rates of decline slowing over time, imply an increase ranging between 22.9% and 37.2%. There will be a projected 19,430 with post-stroke dementia in 2046 (95% UI 17,182-21,904), an increase of 69.2% from 2022. In the most optimistic scenario, the increase would be 22.6%, with realistic scenarios implying an increase ranging between 38.9% and 53.2%. Conclusion Future stroke healthcare needs will vary substantially depending on epidemiological trends. A large increase in post-stroke dementia is projected across scenarios. Further work is needed to identify optimal policies to promote continuing decline in stroke incidence.