Alzheimer’s Disease and Related Dementias in Rural U.S. Medicare Populations: A Scoping Review

Background Rural populations in the U.S. face a disproportionate burden of Alzheimer’s Disease and Related Dementias (ADRD), characterized by delayed diagnosis, limited access to care, and high mortality. Medicare data, given their extensive coverage of older adults, are a critical resource for understanding these disparities. However, no previous review has systematically synthesized evidence specific to rural Medicare beneficiaries. This scoping review maps the existing evidence and highlights critical areas where further rural ADRD research is needed. Methods We conducted a systematic search on PubMed, MEDLINE, CINAHL, Scopus, and Web of Science from inception to March 5, 2025. Peer-reviewed studies were included if they examined ADRD outcomes in rural Medicare populations. We extracted and synthesized information on study designs, health outcomes, population characteristics, rurality definitions, risk factors, access to care, quality of services, healthcare utilization, statistical methods, and policies or interventions. Results Thirty-three studies were included, most published after 2019 (72.7%). The predominant study designs were cohort (60.6%) and cross-sectional (30.3%), with heavy reliance on Medicare Fee-for-Service data (84.8%). Cardiovascular disease and diabetes were the most frequently examined comorbidities, each reported in 18.2% of studies. Lifestyle factors were also assessed in 18.2%, whereas environmental exposures (3.0%) were rarely studied. Logistic regression was the most common statistical method (51.5%), followed by linear regression (21.2%) and Cox proportional models (9.1%). However, advanced techniques (e.g., machine learning and causal inference) were largely absent. Only 21.2% evaluated policy interventions. Conclusions Rural Medicare beneficiaries with ADRD remain underrepresented in research despite their disproportionate burden. Future studies should address key gaps, including inconsistent rural definitions, limited consideration of medication use, lifestyle and environmental exposures (natural and built), and rural-specific policy evaluations. There is also a critical need for more advanced methods to disentangle the complex, multilevel drivers of ADRD disparities. Clinical trial number: Not applicable.