Baseline characteristics of patients are shown in Table 1. No significant differences in age or sex were observed among sepsis patients. Presepsin values of survivors were higher than those of non-survivors (Figs. 1, 2).
ROC curve analyses (Table 2) revealed the following cut-off values: 28-day mortality: 1340.0 (pg/ml) for presepsin on Day 1 (AUC, 0.81; sensitivity, 78%; specificity, 75%), 1163.0 (pg/ml) for presepsin on Day 2 (AUC, 0.80; sensitivity, 91%; specificity, 67%); 1819.0 (pg/ml) for presepsin on Day 3 (AUC, 0.91; sensitivity, 86%; specificity, 83%); 3011.0 (pg/ml) for presepsin on Day 5 (AUC, 0.91; sensitivity, 86%; specificity, 100%); 680.0 (pg/ml) for Δpresepsin Day 3-Day 1 (AUC, 0.72; sensitivity, 57%; specificity, 92%); 22.73 (pg/ml) for PNI (AUC, 0.73; sensitivity, 67%; specificity, 75%);
1.00 (pg/ml) for iPS-GPS (AUC, 0.72; sensitivity, 100%; specificity, 47%); 2.00 (pg/ml) for iPS-NLR (AUC, 0.72; sensitivity, 50%; specificity, 86%); 1.00 (pg/ml) for iPS-PLR (AUC, 0.73; sensitivity, 94%; specificity, 41%), 60-day mortality: 1340.0 (pg/ml) for presepsin on Day 1 (AUC, 0.78; sensitivity, 71%; specificity, 75%), 1163.0 (pg/ml) for presepsin on Day 2 (AUC, 0.76; sensitivity, 85%; specificity, 67%), 1156.0 (pg/ml) for presepsin on Day 3 (AUC, 0.83; sensitivity, 90%; specificity, 78%), 3011.0 (pg/ml) for presepsin on Day 5 (AUC, 0.77; sensitivity, 67%; specificity, 100%), and 1.00 for iPS-NLR (AUC, 0.71; sensitivity, 81%; specificity, 52%), 90-day mortality: 1340.0 (pg/ml) for presepsin on Day 1 (AUC, 0.76; sensitivity, 65%; specificity, 75%), 1163.0 (pg/ml) for presepsin on Day 2 (AUC, 0.73; sensitivity, 73%; specificity, 66%), 1156.0 (pg/ml) for presepsin on Day 3 (AUC, 0.83; sensitivity, 91%; specificity, 81%), 1399.0 (pg/ml) for presepsin on Day 5 (AUC, 0.78; sensitivity, 70%; specificity, 79%), and 180-day mortality: 1336.0 (pg/ml) for presepsin on Day 1 (AUC, 0.77; sensitivity, 68%; specificity, 75%), 1163.0 (pg/ml) for presepsin on Day 2 (AUC, 0.75; sensitivity, 76%; specificity, 69%), 1156.0 (pg/ml) for presepsin on Day 3 (AUC, 0.85; sensitivity, 92%; specificity, 83%), 1313.0 (pg/ml) for presepsin on Day 5 (AUC, 0.78; sensitivity, 73%; specificity, 74%), 390.0 (pg/ml) for Δpresepsin Day 3-Day 1 (AUC, 0.73; sensitivity, 58%; specificity, 91%), 1.00 (pg/ml) for iPS-GPS (AUC, 0.71; sensitivity, 96%; specificity, 51%).
Log-rank test also revealed presepsin, Δpresepsin Day 2-Day 1, Δpresepsin Day 3-Day 1, PNI, iPS-GPS, iPS-NLR, iPS-PI, and iPS-PLR as independent predictors of mortality in sepsis patients (Table 3).
Presepsin values, inflammation-based prognostic scores, iPS, Δpresepsin, SOFA, and qSOFA (with P < 0.05 in univariate analysis) were examined further by multivariate logistic regression analysis for mortality (Table 4). Presepsin on Day 1 was found to be a significant independent predictor of 28-day mortality (OR, 1.0025; 95%CI, 1.00005-1.00497; p = 0.046), 60-day mortality (OR, 1.0027; 95%CI, 1.00025–1.00508; p = 0.030), 90-day mortality (OR, 1.0027; 95%CI, 1.00025–1.00508; p = 0.030), and 180-day mortality (OR, 1.0027; 95%CI, 1.00025–1.00508; p = 0.030) (Table 5).
Furthermore, we investigated whether presepsin value on Day 1 is useful for predicting early mortality (i.e., death within 7 days of ICU admission) in sepsis patients. ROC curve analyses (Fig. 3, Tables 6, 7) revealed the following cut-off values: death within 7 days of ICU admission: 1373.0 (pg/ml) for presepsin on Day 1 (AUC, 0.84; sensitivity, 89%; specificity, 77%), 22.73 (pg/ml) for PNI (AUC, 0.70; sensitivity, 67%; specificity, 77%), 2.0 (pg/ml) for iPS-GPS (AUC, 0.76; sensitivity, 56%; specificity, 91%), 2.0 (pg/ml) for iPS-NLR (AUC, 0.79; sensitivity, 56%; specificity, 88%), 2.0 (pg/ml) for iPS-PLR (AUC, 0.80; sensitivity, 44%; specificity, 93%), and 1.0 (pg/ml) for iPS-PI (AUC, 0.74; sensitivity, 100%; specificity, 55%). For death after 7 days since ICU admission, the cut-off was 1152.0 (pg/ml) for presepsin on Day 1 (AUC, 0.71; sensitivity, 71%; specificity, 64%). Presepsin on Day 1 was found to be a significant independent predictor of death within 7 days of ICU admission by multivariate logistic regression analysis (OR, 1.0007; 95%CI, 1.0001–1.0013; p = 0.0320) (Table 8).