Estimated prevalence of underdiagnosed dementia in a multiethnic community-based study

Dementia frequently goes undetected in community settings, particularly among socially disadvantaged populations. Here, we estimated the prevalence of underdiagnosed dementia across diverse sociodemographic determinants of health in the Health and Aging Brain Study-Health Disparities (HABS-HD), a community-based cohort of adults recruited through community outreach in Fort Worth, Texas. We estimated age-specific probabilities of underdiagnosis using Poisson regression models with a log link, including age and sex as covariates. Robust (sandwich) variance estimators were used to obtain standard errors and 95% confidence intervals (CI). Group differences or trends for continuous measures were assessed using robust variance estimates. The prevalence of underdiagnosed dementia was higher among individuals without physician access (98.1% vs. 78.1%, p<.0001), non-English speakers (97.9% vs. 76.8%, p<.0001), and the uninsured (91.5% vs. 79.5%, p=.03). Black and Hispanic participants also showed higher prevalence (85.8% and 90.9%) compared to non-Hispanic White participants (64.9%; p=.02 and p=.002, respectively). Each additional year of education was associated with a 2.5% lower risk of underdiagnosis (p<.0001). No differences were observed by sex, marital status, income or social support. Our results highlight that several sociodemographic factors contribute to the likelihood of living with undiagnosed dementia.