Cost-effectiveness analysis of blood-based biomarker testing in the diagnosis of Alzheimer's disease pathology

We aimed to evaluate the cost-effectiveness of blood-based biomarker (BBM) testing vs amyloid positron emission tomography (PET) in patients with signs and symptoms of cognitive decline in a neurologist/specialist care setting.

We constructed a decision-tree model to compare diagnostic outcomes and costs of two testing strategies: BBM testing with confirmatory PET scan vs PET scan alone. Their cost-effectiveness was evaluated from a payer perspective with test performance taken from a clinical study and costs including testing/imaging and physician fees.

When access to PET scans is unlimited, BBM triage testing would identify 98.2 % of PET+ patients with a lower average cost per diagnosis compared with PET scan alone ($8868 vs 10,345 per PET+ diagnosis). In terms of incremental cost-effectiveness, BBM triage testing would save $93,984 for each loss of PET+ diagnosis (9.1 times the average cost per PET+ diagnosis by PET scan). Under limited capacity of PET scans, more test-positive patients could be identified using BBM testing than PET scan alone. When access to PET scans is limited to 50 % of the patients, BBM testing would identify 90.6 % more test-positive patients (at 93 % sensitivity) at an incremental cost-effectiveness ratio of $3484 per gain of positive diagnosis, lower than the average cost of a PET+ diagnosis by PET scan ($10,938).

BBM testing, compared with PET scan alone, is more efficient in the utilization of available amyloid PET scans and is cost-effective for assessment of Alzheimer's disease pathology in patients with signs and symptoms of cognitive decline.