Forecast of dementia prevalence in Germany and subnational regions until 2060 using microsimulation

Background: The number of dementia cases is expected to rise in ageing societies with concomitant requirements for healthcare planning. While national figures for countries are widely available, subnational regional heterogeneity is rarely considered. This study aimed at projecting national and subnational dementia figures under different scenarios. Methods: Dementia and population figures where projected from 2018 to 2060 by microsimulation at the level of 400 counties within Germany. The German MikroSim model was supplemented with dementia-specific data on regional prevalence and national incidence and mortality figures. These data were derived from routine health insurance records of 27 million individuals within the AOK fund during pre-pandemic years 2017 to 2019 and adjusted to the total population of 2018. Scenarios with increasing life expectancy or prevention effects (decreasing dementia incidence by 1 to 2 percent per year) were calculated. Results: Increasing life expectancy leads to dementia cases rising from 1.4 million in 2018 to 2.1 million in 2060, prevalence from 1.6 to 2.6 percent and the ratio of cases per 100 individuals of working age RWA from 2.6 to 4.7. In prevention scenarios, these figures are substantially lower: between 1.3 and 1.5 million cases, 1.6 and 1.9 percent prevalence and RWA between 2.9 and 3.4. Existing subnational regional differences in prevalence and RWA will become more pronounced in all scenarios. Conclusion: Growing life expectancy leads to an increase in dementia cases, which may be counteracted by preventive measures. Increasing regional heterogeneity in prevalence and RWA should be considered for health care planning.