Improving Alzheimer Disease Diagnosis Through Efficient Referrals of Blood Tests: Soeren Mattke, MD, DSc

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"By combining cognitive assessments with blood tests in primary care, we can prioritize patients for specialist referrals more efficiently and reduce wait times."

As treatments for patients with Alzheimer disease (AD) are becoming more available, several clinicians have raised concerns about wait times in patient’s diagnostic journey because of the limited amount of AD specialists and PET scanners. A new study reported that the introduction of a high-performance blood test in primary care settings could potentially reduce wait times substantially and prevent eligible patients from falling outside the treatment window.¹ Based on these findings, investigators plan to assess additional scenarios and patient pathways as well as their cost implications in ongoing research.

In the study, authors used a Markov model to estimate wait times for patients eligible for AD treatment. Researchers assumed patients would have a brief cognitive assessment in primary care and be referred to an AD specialist under 3 scenarios including no blood test, blood test to rule out AD pathology, and blood test to confirm AD pathology. Investigators modeled the population aged 55 years and older from 2023 to 2032 in the U.S., assuming 25% of all had never been assessed for cognitive decline, and 5% who were previously cognitively normal, would experience a brief cognitive test.

If the patients had early-stage cognitive impairment and a blood test that indicated AD, 80% would be referred to an AD specialist. The AD specialist would evaluate the patient and order biomarker testing for 90% of those with confirmed early-stage cognitive impairment. The biomarker testing included cerebrospinal fluid testing (10%) and PET imaging (90%). Patients would then return to the AD specialist to have a conversation about the tests’ findings and next steps for treatment. Authors noted that if the blood test were utilized to confirm AD pathology, the patients would skip the first visit to the AD specialist.

These findings were presented at the 2024 Alzheimer’s Association International Conference, July 28 to August 1, in Philadelphia, Pennsylvania, by lead author Soeren Mattke, MD, DSc, director of the University of Southern California (USC) Brain Health Observatory, and colleagues. Prior to the conference, Mattke, who also serves as a research professor of economics at USC, sat down with NeurologyLive^® in an interview to discuss the current challenges in diagnosing AD at the primary care level. He also talked about how blood tests could improve the referral process for patients with AD, according to the findings from the presented study. Moreover, Mattke spoke about the potential impact of better triage methods could have on wait times and treatment initiation for patients living with AD.

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REFERENCES
1. Mattke S, et al. Impact of a High-Performing Blood Test on Wait Times for Determination of Eligibility for a Disease-Modifying Alzheimer’s Treatment in the U.S. Presented at: 2024 Alzheimer’s Association International Conference; July 18 to August 1; Philadelphia, Pennsylvania. Abstract 91612.