Extended Data Fig. 4: Boxplots of plasma p-tau217/Aβ42 (Lumipulse) concentrations with AD pathology as grouping variable.

Boxplots of plasma p-tau217/Aβ42 (Lumipulse) concentrations in the (a) pooled secondary care cohort (n = 911) and (b) primary care cohort (n = 502) with AD pathology as grouping variable. Plasma p-tau217/Aβ42 differed significantly ( P < 0.001) between AD positive and AD negative participants in both populations. Dashed lines represent the single cutoff at 90% specificity established in the Malmö secondary care cohort. The dots represent individual participants. The central band of the boxplot represents the group median, the box limits correspond to the first and third quartiles, and the whiskers represent the minimum/maximum value or the 1.5 interquartile range (IQR) from the box, whichever is smaller. AD pathology was defined as CSF Aβ42/p-tau181 < 11.94 or positive amyloid PET visual read for those who did not undergo lumbar puncture. Group mean levels were compared with Student’s t-test. N = 10 outliers are not shown to improve visualization, but individuals were used in the analyses. One outlier (0.156) was AD pathology-negative. The remaining 9 outliers corresponded to AD pathology-positive participants, with the following plasma p-tau217/Aβ42 levels: 0.223, 0.256, 0.260, 0.273, 0.287, 0.509, 0.671, 0.761, 0.872. All outliers had MCI or dementia. Abbreviations: AD, Alzheimer’s disease; CKD, chronic kidney disease; IQR, interquartile range.