Biomarkers.

Area of Science:

• Neurology
• Biomarker Discovery
• Diagnostic Technologies

Background:

• The advent of disease-modifying therapies for Alzheimer's disease (AD) has heightened the need for accurate and timely diagnosis.
• Current AD diagnostic pathways often lack early assessment of amyloid pathology before confirmatory tests.
• The standard of care (SoC) relies on clinical, cognitive, and imaging assessments.

Purpose of the Study:

• To evaluate the impact of incorporating a plasma-based rule-out test for amyloid pathology into the US healthcare system.
• To assess changes in diagnostic performance and healthcare resource utilization compared to the SoC.
• To analyze diagnostic outcomes across various prevalence and care settings.

Main Methods:

• A cohort-based model simulating 1000 patients with early AD symptoms was developed.
• The model compared the introduction of an Elecsys pTau181 plasma rule-out test against the SoC.
• Scenarios included varying amyloid pathology prevalence (10% to 50%) and care settings (primary and secondary care).

Main Results:

• The plasma rule-out test enhanced diagnostic accuracy, increasing true positives and reducing false negatives across scenarios.
• Significant reductions in healthcare visits (1.8-5.3%) and procedures (1.5-3.6%) were observed.
• Primary care settings, particularly those with lower prevalence, showed the greatest improvements in timely and accurate AD diagnoses.

Conclusions:

• Implementing a plasma rule-out test in the AD diagnostic pathway improves accuracy and efficiency.
• The test is particularly beneficial in low-prevalence settings, optimizing clinical strategies.
• This approach aids healthcare providers in refining diagnostic pathways and resource allocation for AD.