Cover: Modeling Early Detection and Geographic Variation in Health System Capacity for Alzheimer's Disease–Modifying Therapies

Modeling Early Detection and Geographic Variation in Health System Capacity for Alzheimer's Disease–Modifying Therapies

Published Jan 30, 2024

by Jodi L. Liu, Lawrence Baker, Annie Chen, Jessie Wang, Federico Girosi

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Research Questions

  1. How does primary care capacity for early detection of patients with mild cognitive impairment due to AD affect the delivery of Alzheimer's therapies?
  2. How do varying patient care-seeking behaviors for cognitive assessment affect the delivery of Alzheimer's therapies?
  3. What is the variation in health system capacity for early detection, diagnosis, and treatment of early-stage AD across the United States?

Widespread availability of effective disease-modifying therapies (DMTs) would be a breakthrough in slowing the progression of early-stage Alzheimer’s disease (AD) to later stages of dementia. An AD DMT has received traditional approval from the Food and Drug Administration, and more candidates are on the horizon. The authors used a simulation model to assess patient demand and provider supply for the delivery of AD DMTs. They expanded on prior modeling by including the capacity of primary care practitioners (PCPs) who perform brief cognitive assessments and by utilizing county-level data.

The results suggest that engaging the primary care workforce in the diagnostic process would be vital to accelerate the delivery of AD DMTs, which will overwhelm neurology and geriatric practices that often already have wait lists for appointments. Under the base case assumptions, the states with the longest wait times are Alaska, Arkansas, Idaho, Mississippi, Montana, Nevada, Oklahoma, and Wyoming. Primary care models and telehealth models could help improve access to care in these areas. Further work is needed to evaluate how primary care–led models of care can widely and effectively evaluate and manage treatment for people with early-stage AD, as well as how technological advancements, such as improved biomarkers and computerized testing, can be integrated into workflows.

Key Findings

  • There is substantial variation in health care system capacity across the United States to detect, diagnose, and treat early-stage AD with DMTs.
  • The estimated wait times and the number of patients treated are sensitive to patient uptake of brief cognitive assessments.
  • Estimated average wait times vary by state and can be three times longer in rural areas than in urban areas.
  • Care models that enable PCPs to diagnose and evaluate patients for treatment eligibility would make the biggest impact on reducing wait times for specialists and increasing the number of people treated from 2025 through 2044 in the analysis. Improved triage of patients using blood-based biomarker tests could further reduce caseloads for specialists.
  • Widespread delivery of AD-modifying therapies will require a combination of strategies to communicate the value of detection and treatment to patients, integrate PCPs into the detection and diagnosis pathway, and address capacity disparities across the United States.

Research conducted by

This research was sponsored by Genentech and conducted within the Access and Delivery Program of RAND Health Care.

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