Fig. 5
Evolution of the plasma IPMS-Shim Aβ42 biomarker through time and ability to discriminate AD subjects. A Variation in IPMS-Shim Aβ42 concentrations after a median of 741 (172–783) days in AD subjects. B Evolution in IPMS-Shim Aβ42 levels after a median of 631 (366–773) days in non-AD subjects. Results are boxplots with individual values at baseline and follow-up, and mean ± SD are indicated below with n = 10 and 19. Dotted lines connect the values of the same individual. Horizontal boxplots represent delay distribution. The decline was expressed as a linear function because only two time points were available. Wilcoxon signed-rank test for paired data. C Change (Δ) in IPMS-Shim Aβ42 for the AD and non-AD groups. One-sample Mann–Whitney test, #p < 0.05; Mann–Whitney test, *p < 0.05. D ROC/AUC analysis of the change in IPMS-Shim Aβ42 between AD and non-AD groups. AUC is presented with 95% confidence interval (CI). The best values for sensitivity (se) and specificity (sp) were computed at an optimal cutoff point determined using Youden’s index