Predicting cognitive decline with amyloid‐PET, plasma p‐tau217, Aβ42/40, and p‐tau217/Aβ42 in a community‐based cohort – relevance for clinical trial enrollment

Aβ SUVR, plasma p-tau217, and the p-tau217/Aβ42 ratio predicted decline across multiple cognitive domains. Using cohort-specific biomarker cutoffs, sample size estimates were similar for p-tau217 combined with Aβ42/40 or Aβ SUVR. A multidomain composite best detected AD-related decline. Outcome measures and eligibility criteria strongly impact sample size estimates, especially in CU.