Fig. 2

Exploration of Two-Point Thresholds for Plasma p-tau217. A In order to examine different thresholds of sensitivity and specificity, we considered performance of plasma p-tau217 at three thresholds: (i) 90% sensitivity and 90% specificity; (ii) 95% sensitivity and 95% specificity; (iii) 97.5% sensitivity. Those above these specificity and below these sensitivity cut-offs were judged to have high risk and low risk of CSF-determined Aβ positivity respectively. Shaded areas indicate those in the intermediate category, with scores above the specified sensitivity cut-off but below the specificity cut off. B Tabular results obtained by applying these cut-offs indicating low, intermediate and high risk of CSF-determined Aβ, presented by CSF-defined Aβ status. C Positive Predictive Accuracy (PPA), Negative Predictive Accuracy (NPA) and Overall Percent Agreement for p-tau217 positive and negative participants are provided at each threshold