External Validation and Recalibration of the CURB-65 and PSI for Predicting 30-Day Mortality and Critical Care Intervention in Multiethnic Patients with COVID-19

Abstract

Objectives To validate and recalibrate the CURB-65 and pneumonia severity index (PSI) in predicting 30-day mortality and critical care intervention (CCI) in a multiethnic population with COVID-19, along with evaluating both models in predicting CCI. Methods Retrospective data was collected for 1181 patients admitted to the largest hospital in Qatar with COVID-19 pneumonia. The area under the curve (AUC), calibration curves, and other metrics were bootstrapped to examine the performance of the models. Variables constituting the CURB-65 and PSI scores underwent further analysis using the Least Absolute Shrinkage and Selection Operator (LASSO) along with logistic regression to develop a model predicting CCI. Complex machine learning models were built for comparative analysis. Results The PSI performed better than CURB-65 in predicting 30-day mortality (AUC 0.83, 0.78 respectively), while CURB-65 outperformed PSI in predicting CCI (AUC 0.78, 0.70 respectively). The modified PSI/CURB-65 model (respiratory rate, oxygen saturation, hematocrit, age, sodium, and glucose) predicting CCI had excellent accuracy (AUC 0.823) and good calibration. Conclusions Our study recalibrated, externally validated the PSI and CURB-65 for predicting 30-day mortality and CCI, and developed a model for predicting CCI. Our tool can potentially guide clinicians in Qatar to stratify patients with COVID-19 pneumonia.

External validation of risk scores to predict in-hospital mortality in patients hospitalized due to coronavirus disease 2019

“… [33] Lastly, in a cohort of 1181 patients from Qatar, a C-statistic of 0.78 (95% CI 0.70-0.86) was reported. [34] Overall, the discriminative performance of the CURB-65 reported by these studies varied from moderate to good. Similar to our study, none of the aforementioned studies assessed model calibration of the CURB-65 score.…”

A Simple Prognostic Score for Critical COVID-19 Derived from Patients without Comorbidities Performs Well in Unselected Patients

“…Aging, male sex, cardiovascular risk factors and cardiovascular disease, kidney and lung dysfunction, cancer and autoimmune diseases have been associated with worse clinical outcomes among patients with COVID-19 [ 2 , 5 , 23 ]. In the presence of comorbidities, the classic pneumonia scores such as CURB-65 and PSI [ 24 , 25 ] as well as a quicker clinical score, namely qSOFA [ 26 , 27 ], have shown a good correlation with poor prognosis. However, so far no study has investigated a cohort free of comorbidities and stable admission criteria, homogeneous and stable therapeutic approach.…”

Differences in inflammatory markers between coronavirus disease 2019 and sepsis in hospitalised patients

“…Recently, Elmoheen et al reported that CURB-65 outperformed pneumonia severity index in predicting 30-day mortality and critical care intervention in a multiethnic population from Qatar (2021). 31 Besides the CURB-65 score, it could be studied if including procalcitonin, D-dimer, and ferritin could help predict sepsis's inflammatory and coagulation states. Additionally, other scores, such as sequential organ failure assessment (SOFA), could be used for further evaluation of patients in the intensive care setting.…”