Incidence and Prevalence of Dementia With Lewy Bodies

Importance: Reliable global estimates of the incidence and prevalence of dementia with Lewy bodies (DLB) are lacking, limiting understanding of its epidemiology and burden. Objective: To estimate pooled incidence and prevalence of DLB from population-based studies worldwide, overall and by age and sex. Data Sources and Study Selection: PubMed, Embase, and Scopus were systematically searched from inception to October 22, 2024, for population-based studies reporting DLB incidence and/or prevalence based on validated diagnostic criteria. Data Extraction and Synthesis: Three reviewers independently screened studies, extracted data, and assessed risk of bias according to PRISMA guidelines. Incidence and prevalence estimates were pooled using random-effects meta-analysis. Subgroup and sensitivity analyses explored variation by age, sex, and study design. Main Outcomes and Measures: Incident and prevalent DLB cases defined by consensus, Diagnostic and Statistical Manual of Mental Disorders or International Classification of Diseases diagnostic criteria, with denominators based on census or author-defined population at risk. Results: From 2520 records screened, 16 population-based studies were included and 12 contributed to meta-analyses. In individuals 65 years or older, pooled incidence was 46.85 per 100 000 person-years (95% CI, 23.78-92.30) and pooled prevalence 352.26 per 100 000 population (95% CI, 112.25-1099.79). In individuals younger than 65 years, pooled incidence was 0.34 per 100 000 person-years (95% CI, 0.14-0.83) and prevalence 2.52 per 100 000 population (95% CI, 1.43-4.44). Incidence was higher in males (5.45; 95% CI, 4.13-7.19) than females (4.32; 95% CI, 2.48-7.52). Across all ages, pooled crude incidence was 4.79 (95% CI, 3.90-5.88). Only 1 study reported all-age prevalence (19.13; 95% CI, 15.38-23.51). Between-study heterogeneity was high (I2 ≥ 85%). Conclusions and Relevance: In this systematic review and meta-analysis of population-based studies, clinically diagnosed DLB was uncommon, likely reflecting underdiagnosis and diagnostic insensitivity. Reported incidence and prevalence rose steeply with age, were higher in men, and varied widely across settings. These findings provide a robust reference for future epidemiologic research and public health planning, underscoring the need for standardized diagnostic approaches and inclusion of underrepresented populations to refine global burden estimates.