Procalcitonin (PCT) Improves the Accuracy and Sensitivity of CURB-65 Score in Predicting CAP Patients Admission to ICU

Background: The CURB-65 scoring system is a simple tool for assessment and prognosis prediction for communi-ty-acquired pneumonia (CAP) patients. However, the variations in the performance of CURB-65 in young and el-derly patients, underestimation, or overestimation of the severity have often been reported. It is worth noting that the application of biomarkers is helpful for improving the accuracy of the scoring system. In recent years, more and more reports and studies paid attention to procalcitonin (PCT) in respiratory infectious diseases, and its clini-cal value has attracted increasing attention. The study aimed at investigating the effectiveness of the CURB-65 score combined with PCT in predicting admission of CAP patients to intensive care units (ICU).Methods: We conducted a retrospective study. We analyzed data from 520 non-immune individuals over the age of 18 in this study. All patients received blood indicators measurement and CURB-65 score calculation on admission. The primary outcome used to assess the probability of a CAP patient was who would get a bed in general ward or ICU. Receiver operating characteristic curves (ROC) were used to evaluate the sensitivity and specificity of the CURB-65 model and PCT combined CURB-65 augmented model in predicting the main outcomes.Results: After analyzing the data from 520 patients, we found that the probability of entering the ICU was 22.1% (115/520). The AUC of Combination 1 (PCT&CURB-65 scores), Combination 2 (WBC&CURB-65 scores), Combi-nation 3 (hs-CRP&CURB-65 scores) and Combination 4 (D-dimer&CURB-65 scores) for predicting CAP patients entering the ICU was 0.92 (95% CI 0.88 -0.95), 0.91 (95% CI 0.87 -0.94), 0.89 (95% CI 0.85 -0.92), and 0.90 (95% CI 0.87 -0.94), respectively, with statistically significant differences (p = 0.00); the sensitivities were 0.83, 0.82, 0.77 and 0.77, respectively, and the specificities were 0.92, 0.84, 0.90 and 0.91, respectively. PCT was superior to other indexes to improve the sensitivity and specificity of the CURB-65 score.Conclusions: Procalcitonin improves the accuracy and sensitivity of the CURB-65 score in predicting the proba-bility of CAP patients entering the ICU, and PCT was superior to other indexes to improve the sensitivity and specificity of the CURB-65 score.