Alzheimer’s Blood Biomarker Models Lose Rule-Out Power Across Cohorts
A 2026 ADNI/A4 validation study found that Alzheimer’s plasma-biomarker machine-learning models still ranked amyloid PET status well across cohorts, but the practical rule-out number moved hard: negative predictive value fell from 0.831 inside ADNI to 0.644 when the ADNI-trained model was applied to A4.1 Research Highlights 1,707-person ADNI/A4 test: researchers trained amyloid PET prediction models …