Molecular and statistical weaknesses of the p-tau217/Aβ1−42 plasma ratio for alzheimer’s diagnosis

ratio is best regarded as a useful contextual or research tool rather than a standalone diagnostic benchmark, so that precision medicine does not rest on associations whose causal and mechanistic basis remains insufficiently established. Its most appropriate use may be in longitudinal monitoring within the same individual, where changes over time may be more informative than a single threshold-based diagnostic result.