PRL and delirium: The thresholds optimizing the Youden index (Zhou et al., 2011) for the three biomarkers are TARDBP (delirium if ≤0.33 with the max Youden index = 0.55), YARS2 (delirium if ≥−0.22 with the max Youden index = 0.5), and PRL (delirium if ≥0.39 with the max Youden index = 0.5).