Prognostic value of CURB-65 and pneumonia severity index (PSI) in COVID-19 pneumonia: A retrospective cohort study

Abstract

Objective: To validate a better scoring system between CURB-65 and the pneumonia severity index (PSI) to predict the need for intensive care unit admission and 30-day mortality in patients with COVID-19 pneumonia. Methods: A retrospective cohort study was conducted on patients in a tertiary care hospital in Kota, Rajasthan. Relevant data about history, and general and systemic examination with laboratory investigations was collected. Patients were categorized into different risk groups for ICU admission and 30-day mortality according to CURB-65 and PSI. Sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve were calculated. Continuous variables, means and percentages were compared using the t-test for numerical data and the Chi-square test for nominal data. Results: 100 patients who tested positive for SARS-CoV-2 by RT-PCR were included; 67 were male and 33 were female. 58 patients had severe disease (SpO2≤90%) and 30 patients died. CURB-65 had an area under the curve (AUC) of 0.81 for predicting ICU admission, with a sensitivity of 92% and a specificity of 54% for high risk patients. Meanwhile, PSI had an AUC of 0.88, with a sensitivity of 83% and a specificity of 73% in high risk patients. In addition, CURB-65 had an AUC of 0.79 for predicting 30-day mortality, with a sensitivity of 60% and a specificity of 89% in high risk patients. PSI had an AUC of 0.71 for predicting 30-day mortality, with a sensitivity of 90% and a specificity of 46% in high risk patients. Conclusions: This single-centre retrospective study involving a cohort of COVID-19 patients demonstrates that CURB-65 and PSI are powerful tools for predicting mortality. However, PSI appears to be slightly better at predicting the need for intensive care unit admission in high-risk patients.