CURB-65 may serve as a useful prognostic marker in COVID-19 patients within Wuhan, China: a retrospective cohort study

Abstract

A recently developed pneumonia caused by SARS-CoV-2 has quickly spread across the world. Unfortunately, a simplified risk score that could easily be used in primary care or general practice settings has not been developed. The objective of this study is to identify a simplified risk score that could easily be used to quickly triage severe COVID-19 patients. All severe and critical adult patients with laboratory-confirmed COVID-19 on the West campus of Union Hospital, Wuhan, China, from 28 January 2020 to 29 February 2020 were included in this study. Clinical data and laboratory results were obtained. CURB-65 pneumonia score was calculated. Univariate logistic regressions were applied to explore risk factors associated with in-hospital death. We used the receiver operating characteristic curve and multivariate COX-PH model to analyse risk factors for in-hospital death. A total of 74 patients (31 died, 43 survived) were finally included in the study. We observed that compared with survivors, non-survivors were older and illustrated higher respiratory rate, neutrophil-to-lymphocyte ratio, D-dimer and lactate dehydrogenase (LDH), but lower SpO2 as well as impaired liver function, especially synthesis function. CURB-65 showed good performance for predicting in-hospital death (area under curve 0.81, 95% confidence interval (CI) 0.71-0.91). CURB-65 ⩾ 2 may serve as a cut-off value for prediction of in-hospital death in severe patients with COVID-19 (sensitivity 68%, specificity 81%, F1 score 0.7). CURB-65 (hazard ratio (HR) 1.61; 95% CI 1.05-2.46), LDH (HR 1.003; 95% CI 1.001-1.004) and albumin (HR 0.9; 95% CI 0.81-1) were risk factors for in-hospital death in severe patients with COVID-19. Our study indicates CURB-65 may serve as a useful prognostic marker in COVID-19 patients, which could be used to quickly triage severe patients in primary care or general practice settings.

Keywords: COVID-2019; CURB-65; SARS-CoV-2; death; prognosis.

Fig. 1.

Patient flowchart.

Fig. 2.

CURB-65 distribution for survivors and non-survivors. The distribution of patients with different CURB-65 score ranges was compared in survivors and non-survivors. In survivors, 81% had a CURB-65 score 0 or 1, 19% had a CURB-65 score 2. In non-survivors, 32% had CURB-65 score 0 or 1, 42% had CURB-65 score 2, while 26% had CURB-65 score 3.

Fig. 3.

Univariate analysis of risk factors for in-hospital death. Significant variables in univariate analysis were plotted as a forest plot. The second column listed the AUC of all risk factors, the third column listed OR and 95% CI for all risk factors. Note: Those factors with extremely wide CI were ignored in the plot.

Fig. 4.

Kaplan–Meier curve for death and CURB-65 categories. Survival analysis for patients categorised by the CURB-65 score. Patients with CURB-65 ⩾2 had significantly lower survival probability than those with CURB-65 <2 (P < 0.05).