Population Attributable Fraction of poor sleep quality and its association with dementia: a Brazilian population-based study.

The populational impact of sleep quality and the risk of dementia is unclear. We analyzed the Population Attributable Fraction (PAF) of sleep parameters in a large-scale Brazilian cohort (ELSI-Brazil). A subset of the ELSI-Brazil with complete responses to sleep quality was selected. This is a large representative sample of the Brazilian elderly population with an extensive assessment of sociodemographic and health risk variables. Prevalence was estimated according to the complex sample design, and its PAF was measured using a meta-analytic relative risk. A total of 6024 (out of 9412) individuals had complete responses. The prevalence of poor sleep quality was 24.9% (95%CI 23–26%), and the PAF of poor sleep quality including 10 modifiable risk factors of dementia was 52% in Brazil. Sleep parameters varied considerably according to age ranges, race, and gender. Poor sleep quality appears to be an important populational risk factor for dementia in Brazil. Targeted interventions may provide an important impact in preventing dementia in low- and middle-income countries.