Disparities in Access to Diagnostic Evaluation for Alzheimer's Disease in Individuals Dually Eligible for Medicare and Medicaid: A Modeling Study.

Background: Individuals dually eligible for Medicare and Medicaid (duals) may face greater obstacles to access to disease-modifying Alzheimer's treatments in spite of their higher disease burden, because of clinicians' reluctance to accept Medicaid and the so-called "lesser of" policy, under which Medicaid may pay providers lower rates. Objective: To project differential wait times for duals compared to Medicare-only beneficiaries by state. Methods: We used State Medicaid payment policy and Medicare enrollment data and a Markov model to predict differential wait times for duals and non-duals from 2023 to 2050. We estimated available diagnostic appointments by state for both groups based on reluctance of clinicians to accept Medicaid and the "lesser of" policy for each year. Results: We estimate overall average wait times of almost two years (22.9 months) but almost three times as long for duals (59.8 months) than non-duals (20.7 months) because of higher disease burden. The effects of Medicaid payment policy would increase average wait times for duals to 89 months with 20 states having wait times of 99 months or more, which would effectively deprive duals of access. Conclusions: The added average wait times in many states would effectively deprive duals from access to treatment and translate into avoidable disease progression and mortality. Policy interventions to reduce financial and nonfinancial obstacles are dearly needed to avoid deepening disparities. Examples are coverage arrangements that integrate Medicare and Medicaid coverage, covering the co-payment for physician services in full, and stricter network adequacy requirements for Medicaid Managed Care plans.