Introduction Individualized estimates of age at detectable amyloid-beta (Aβ) accumulation,
distinct from amyloid positivity, allow for analysis of onset age of Aβ accumulation as an
outcome measure to understand risk factors. Methods Using longitudinal Pittsburgh
compound B (PiB) positron emission tomography data from Baltimore Longitudinal Study of
Aging, we estimated the age at which each PiB+ individual began accumulating Aβ. We
used survival analysis methods to quantify risk of accumulating Aβ and differences in onset …