ObjectiveTo compare and evaluate the diagnostic value of procalcitonin(PCT) and soluble triggering receptor expressed on myeloid cells-1(sTREM-1) for ventilator-associated pneumonia(VAP). MethodsThe related studies were systematically searched in PubMed, OvidSP (EMBASE), Cochrane Library, clinicaltrials.gov, EBSCO, CBM, CNKI and Wanfang database and the methodological quality of all eligible studies were assessed using the Quality Assessment for Studies of Diagnostic Accuracy (QUADAS) tool. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR), and areas under the summary receiver operating characteristic (sROC) curve of PCT and sTREM-1 were pooled by Meta-disc software, respectively. Area under the sROC curve (AUC) was compared using Z-test. In addition, Bayes's theorem was used to calculate the probability of VAP, conditioned by the likelihood ratio as a function of the pretest probability. ResultsIn total, 31 studies were included (20 studies on PCT and 11 studies on sTREM-1). The combined sensitivity, specificity, DOR and AUC of diagnosing VAP by PCT was 0.78, 0.74, 15.21, and 0.868, respectively. And the combined sensitivity, specificity, DOR and AUC of diagnosing VAP by sTREM-1 was 0.88, 0.80, 30.28, and 0.919, respectively. There was no statistical difference between two areas under the sROC curve (P=0.25). ConclusionsTREM-1 is superior to PCT in diagnosing VAP, however, neither can confirm nor exclude VAP alone.