Early cost-utility analysis of general and cerebrospinal fluid-specific Alzheimer's disease biomarkers for hypothetical disease-modifying treatment decision in mild cognitive impairment.

INTRODUCTION: The study aimed to determine the room for improvement of a perfect cerebrospinal fluid (CSF) biomarker and the societal incremental net monetary benefit of CSF in subjects with mild cognitive impairment (MCI) assuming a hypothetical disease-modifying Alzheimer's disease (AD) treatment. METHODS: A decision model compared current practice to a perfect biomarker and to two strategies positioning CSF as add-on test when current practice concluded the presence or absence of AD. RESULTS: The simulated MCI population was aged on average 68.3 and 49% had AD. The room for improvement by the perfect CSF test was 0.39 quality adjusted life years, €33,622 ($43,372) savings, 2.0 potential beneficial treatment years, and 1.3-year delay in dementia conversion. DISCUSSION: The results indicated more potential benefit from a biomarker positioned to verify subjects who are not expected to have AD (i.e., to prevent undertreatment) rather than to verify subjects expected to have AD (prevent overtreatment). Sensitivity analyses explored different CSF positions.