BackgroundBlood tests for Alzheimer's disease (AD) are emerging as alternative to amyloid positron emission tomography (PET) scans and analysis of cerebrospinal fluid (CSF). However, their effect on clinical decision-making and subsequent wait times in the diagnostic process remain unclear.ObjectiveTo estimate wait times in the diagnostic process to determine potential eligibility for amyloid-targeting treatments.MethodsWe used a structured expert consultation process to elicit how a blood test to rule out or to confirm AD pathology would inform decisions in primary and secondary care and a Markov model to project how those decisions would affect wait times for specialist visits and amyloid PET scans.ResultsCompared with referral decisions based on the results of a brief cognitive assessment, the addition of an AD blood test is projected to reduce wait times for subsequent specialist appointments by 35%. A blood test for confirmation of AD pathology would also eliminate wait times for amyloid PET scans.ConclusionsHigh-performing AD blood tests have the potential to streamline the diagnostic journey and reduce wait times.
Keywords: Alzheimer's disease; amyloid-targeting treatments; blood biomarker; clinical utility; health system capacity; wait times.