Rural-urban differences in diagnostic incidence and prevalence of Alzheimer's disease and related dementias

Introduction: Understanding rural-urban variation in the diagnostic incidence and prevalence of Alzheimer's disease and related dementias (ADRD) will inform policies to improve timely diagnosis and access to supportive services for older adults in rural communities. Methods: Using 2008 to 2015 national claims data for fee-for-service Medicare beneficiaries (roughly 170 million person-years), we computed unadjusted and adjusted diagnostic incidence and prevalence estimates for ADRD in metropolitan, micropolitan, and rural counties, and examined differences in survival rates. Results: Risk-adjusted ADRD diagnostic incidence was higher in rural versus metropolitan counties despite lower prevalence. Among beneficiaries diagnosed with ADRD in 2008, metropolitan county residents experienced longer survival compared to residents in rural and micropolitan counties. Discussion: These data suggest that older adults in rural communities may be underdiagnosed with ADRD, and/or diagnosed at later stages of dementia. Further work is needed to develop strategies to reduce this disparity.