The Population Attributable Fraction of Dementia From Audiometric Hearing Loss Among a Nationally Representative Sample of Community-Dwelling Older Adults.

BACKGROUND:The population attributable fraction (PAF) of dementia from hearing loss (HL) in the United States is ~2% when incorporating self-reported HL measures. However, self-report might underestimate clinically significant audiometric HL among older adults. Here, we quantified PAFs of dementia from audiometric HL overall and by age, sex, and race/ethnicity groups among a nationally representative sample of community-dwelling older adults in the United States. METHODS:We used cross-sectional data from Round 11 (2021) of the National Health and Aging Trends Study, a prospective cohort study representing the U.S. Medicare population aged 65+ years (N = 2 470). We estimated model-adjusted PAFs of prevalent dementia by audiometric HL (pure-tone averages: normal hearing, <26 dB HL; mild HL, 26-40 dB HL; moderate or greater HL, ≥41 dB HL). RESULTS:Among eligible participants (34.8% aged ≥80 years; 55.3% female; 82.4% non-Hispanic White), 37.5% had mild, and 28.8% had moderate or greater HL. Dementia prevalence overall was 10.6%, with the PAF predominately driven by moderate or greater HL (PAF = 16.9%; 95% confidence interval [CI]: 4.1-28.7%). The PAF from any degree of HL was larger but with a wider CI (PAF = 18.7%, 95% CI: -5.3% to 40.1%). There was evidence associations differed by sex but not age or race/ethnicity; moderate or greater HL exhibited stronger associations among males (PAF = 40.5%; 95% CI: 19.5% to 57.2%) than females (PAF = 3.2%; 95% CI: -12.7% to 17.9%). CONCLUSIONS:In a nationally representative sample of community-dwelling older adults in the United States, 17% of dementia cases were attributable to moderate or greater audiometric HL, an estimate that is eightfold higher relative to studies relying on self-reported hearing measures only.