In a meta-analysis of five studies [18,23,24,25,26] (n = 678) [27], PSP and PCT (respectively, AUROC 0.80–95%CI 0.75–0.85 and AUROC 0.79–95%CI 0.74–0.84) had a better performance than CRP (AUROC 0.56–95%CI 0.50–0.63) in discriminating mild infection from severe infection, sepsis, and septic shock. Here, CRP is linked to infection.