Hendriks S, Peetoom K, Bakker C, et al. - Age-standardized prevalence of young-onset dementia was 119.0 per 100,000 population, in this systematic review and meta-analysis. There were scarce estimates of the prevalence in low-income countries and younger age ranges.

• Relevant population-based studies were identified from PubMed, Embase, CINAHL, and PsycInfo databases.

• Systematic review comprised 95 unique studies, of which 74 including 2,760,379 unique patients were also analyzed in 5-year age band meta-analyses.

• An increase in age-standardized prevalence estimates occurred from 1.1 per 100,000 population in the group aged 30 to 34 years to 77.4 per 100 000 population in the group aged 60 to 64 years.

• Similar prevalence was found between men and women (crude estimates for men, 216.5 per 100,000 population; for women, 293.1 per 100,000 population).

• High-income countries showed a lower prevalence than upper–middle-income and lower–middle-income countries.