Predictive value of platelet-related parameters combined with pneumonia severity index score for mortality rate of patients with severe pneumonia.

Abstract

To analyse the predictive value of platelet-related parameters combined with pneumonia severity index (PSI) score for the mortality rate of patients with severe pneumonia. The clinical data of 428 severe pneumonia patients were retrospectively analysed. They were divided into survivor and death groups according to 28-day prognosis. Platelet-related parameters platelet count (PLT), mean platelet volume (MPV), platelet-large-cell ratio (P-LCR) and platelet distribution width (PDW) were measured within 24 hours after admission. The receiver operating characteristic (ROC) curves were plotted. The areas under the ROC curves (AUC) were used to describe the predictive efficiencies of platelet-related parameters, PSI score and their combination for death within 28 days. On the 28th day, there were 184 deaths and 244 survivors, and the deaths had significantly higher PLT and PSI score but lower PDW, MPV and P-LCR than those of the survivors (P<0.05). The combination of platelet-related parameters and PSI score had the highest sensitivity (96.56%) and specificity (99.34%) and the largest AUC (0.902) for predicting 28-day mortality. PLT, PDW, MPV and P-LCR are significantly abnormal in patients with severe pneumonia, and the combination of platelet-related parameters with PSI score has the highest predictive value for 28-day mortality.