In a large multicenter cohort study, plasma phosphorylated tau 217 (p-tau217) levels were influenced by chronic kidney disease, body mass index, and anemia, and biomarker thresholds adjusted for these factors improved the accuracy and cost-efficiency of amyloid-β pathological classification compared with a single universal cutoff. The double-cutoff approach enhanced diagnostic performance in participants with obesity but increased intermediate results requiring confirmatory amyloid positron emission tomography, highlighting the need for biologically informed p-tau217 cutoff strategies in diverse clinical populations.

Source: JAMA Neurology