Predictive Efficacies of SOFA Score, CURB-65 Score and PSI Score for 28-day Mortality in Patients with Severe Pneumonia: a Comparative Study

Abstract

Background Severe pneumonia is a common critical respiratory illness with high mortality and heavy social burden. Early and accurate assessment of the condition and prognosis of patients with severe pneumonia contributes to clinical decision-making. The Sequential Organ Failure Assessment (SOFA), CURB-65 score, and Pneumonia Severity Index (PSI) score can reflect the severity of pneumonia in different aspects, but there is no consensus on which one of them has the highest performance in predicting the prognosis of severe pneumonia. Objective To explore the predictive efficacy of SOFA, CURB-65 and PSI scores for short-term prognosis of patients with severe pneumonia. Methods This was a multicenter, prospective observational study. Inpatients with severe pneumonia were selected from the ICU and department of respiratory and critical medicine of 11 hospitals (including the First Affiliated Hospital of Henan University of Traditional Chinese Medicine and other 10 hospitals) from December 2017 to March 2022. The patients were divided into survival group and death group according to the 28-day mortality after diagnosis to compare clinical characteristics and SOFA, CURB-65 and PSI scores assessed on the day of hospitalization. The receiver operating characteristic (ROC) curve was used to assess the performance of three risk scores for predicting the 28-day mortality. The predictive efficacy of the risk scores was evaluated using the Hosmer-Lemeshow test and calibration plot. Optimal risk scores were stratified using X-tile 3.6 to determine the optimal threshold. Kaplan-Meier survival curves of the patients were plotted and compared using the Log-rank test. Results A total of 240 patients were included, among whom 57 (23.8%) died within 28 days after diagnosis. Compared with the survival group, the death group had greater average age and lower average platelet count (P<0.05). And the SOFA, CURB-65 and PSI scores in the death group were higher (P<0.05). ROC analysis demonstrated that the values of AUC of SOFA score, CURB-65 score and PSI score were 0.741〔95%CI (0.663, 0.820) 〕, 0.627〔95%CI (0.544, 0.710) 〕, and 0.621〔95%CI (0.539, 0.703) 〕, respectively, all were greater than 0.6, indicating that the three scores had good predictive value for 28-day mortality in severe pneumonia (P<0.001), and the AUC of SOFA score was higher than that of CURB-65 score (Z=2.492, P=0.013) or PSI score (Z=2.775, P=0.006). Both the Hosmer-Lemeshow test and calibration plot suggested that the SOFA score was more accurate. Kaplan-Meier survival analysis showed that 28-day mortalities in low-risk (0-5), moderate-risk (6-8), and high-risk (9-18) patients stratified by SOFA score using the X-tile 3.6 were 12.0% (17/142), 28.8% (19/66), and 65.6% (21/32) respectively (χ2=37.93, P<0.001) . Conclusion SOFA, CURB-65 and PSI score are all suitable for predicting 28-day mortality of patients with severe pneumonia, with SOFA score being more valuable for clinical application.

Keywords

• severe pneumonia|sequential organ failure assessment scores|curb-65 score|pneumonia severity index|prognosis|predictive efficacy|comparative study