Fig. 5: Comparisons between plasma Lumipulse p-tau217 and MS-based p-tau217 and %p-tau217 for discriminating AD pathology-positive versus AD pathology-negative participants.

Data from the pooled secondary care cohorts (n = 619) and the primary care cohort (n = 513) were examined. The secondary care cohorts consisted of participants from the Malmö (n = 337), Gothenburg (n = 164) or Brescia (n = 118) cohort with MS-based data available. Cutoffs were set in the Malmö secondary care cohort (n = 337). a–c, In the single cutoff approach, the cutoffs were >0.27 pg ml⁻¹ for Lumipulse p-tau217, >2.27 pg ml⁻¹ for MS-based p-tau217 and >4.27 pg ml⁻¹ for MS-based %p-tau217. e–h, In the two-cutoff approach, the cutoffs for Lumipulse p-tau217 were <0.22 pg ml⁻¹ and >0.34 pg ml⁻¹, <1.59 pg ml⁻¹ and >2.92 pg ml⁻¹ for MS-based p-tau217 and <3.55 pg ml⁻¹ and >5.08 pg ml⁻¹ for MS-based %p-tau217. Data are presented as the observed percentage and the error bars as the 95% CI derived from the bootstrap distribution. AD pathology was defined as CSF Aβ42:p-tau181 < 11.94 or positive visual read on amyloid PET if lumbar puncture was not performed. To assess whether the observed difference in the statistics is significantly different from zero, we performed a bootstrap hypothesis test. The P value (two sided) was calculated as the proportion of bootstrap resamples (n = 2,000) where the absolute null-distributed statistic was greater than or equal to the observed difference. Differences between AUCs were assessed using DeLong statistics. Results were not corrected for multiple comparisons. Significant P values in the order as presented in the plot: 0.003, <0.001 (a); <0.001 (b); 0.020, 0.004, <0.001 (c); 0.006, 0.025 (d); 0.020 (e); 0.008, 0.006 (f); 0.014 (g); 0.003, <0.001, <0.001, <0.001 (h). ^aSignificantly better than Lumipulse p-tau217, P < 0.05. ^bSignificantly better than MS-based p-tau217, P < 0.05.