Trends in the Incidence of Early- and Late-Onset Dementia in 2011–2019: A Nationwide Population-Based Study

Purpose: To examine secular trends in the incidence of early- (ages 45–64) and late-onset (ages 65+) dementia in Israel from 2011 to 2019 and to assess sex-specific patterns. Methods: A nationwide, population-based study using electronic health records from all four Israeli health maintenance organizations, which provide universal healthcare coverage. Incident cases were identified by International Classification of Diseases (ICD-9/10) codes and/or purchases of anti-dementia medications. Age- and sex-specific incidence rates were calculated, and joinpoint regression models were used to assess trends over time. Results: Over the 9-year period, dementia incidence declined significantly in both early- and late-onset groups. Mean annual incidence per 100 individuals was 0.04 for early-onset dementia overall (0.05 in men, 0.04 in women), and 1.55 for late-onset dementia (1.35 in men, 1.72 in women). Statistically significant annual percentage changes (APCs) were observed across most age groups, with the sharpest declines in those aged 65–74 (−4.0% per year) and 75–84 (−4.1% per year). Among adults aged 85+, incidence was stable from 2011–2015, followed by a significant decline from 2015–2019 (−6.6% per year). These trends were consistent across sexes. Conclusions: These findings highlight important public health and community health implications, underscoring the need for continued dementia surveillance, early detection, and evidence-based policy to support healthy aging.