Background: New research criteria for the diagnosis of Alzheimer's disease (AD) have recently
been developed to enable an early diagnosis of AD pathophysiology by relying on emerging
biomarkers. To enable efficient allocation of health care resources, evidence is needed to
support decision makers on the adoption of emerging biomarkers in clinical practice. The
research goals are to 1) assess the diagnostic test accuracy (of current clinical diagnostic
work-up and emerging biomarkers in Magnetic Resonance Imaging (MRI), Positron Emission
Tomography (PET) and Cerebrospinal Fluid (CSF), 2) perform a cost-consequence analysis and 3)
assess long-term cost-effectiveness by an economic model.
Methods/design: In a cohort design 304 consecutive patients suspected of having a primary
neurodegenerative disease are approached in four academic memory clinics and followed for two
years. Clinical data and data on quality of life data, costs and emerging biomarkers are
Diagnostic test accuracy is determined by relating the clinical practice and new research
criteria diagnoses to the reference diagnosis. The clinical practice diagnosis at baseline is
reflected by a consensus procedure among experts using clinical information only (no
biomarkers). The diagnosis based on the new research criteria is reflected by decision rules
that combine clinical and biomarker information. The reference diagnosis is determined by a
consensus procedure among experts based on clinical information on the course of symptoms
over a two-year time period.
A decision analytic model is build combining available evidence from different resources
among which (accuracy) results from the study, literature and expert opinion to assess
long-term cost-effectiveness of the emerging biomarkers.
Discussion: Several other multi-centre trials study the relative value of new biomarkers for
early evaluation of AD and related disorders. The uniqueness of this study is the assessment
of resource utilization and quality of life to enable an economic evaluation. The study
results are generalizable to a population of patients who are referred to a memory clinic due
to their memory problems.