Utility of severity assessment tools in COVID-19 pneumonia: a multicentre observational study

Abstract

Background: Severity scores in pneumonia and sepsis are being applied to SARS-CoV-2 infection. We aimed to assess whether these severity scores are accurate predictors of early adverse outcomes in COVID-19.

Methods: We conducted a multicentre observational study of hospitalised SARS-CoV-2 infection. We assessed risk scores (CURB65, qSOFA, Lac-CURB65, MuLBSTA and NEWS2) in relation to admission to intensive care or death within 7 days of admission, defined as early severe adverse events (ESAE). The 4C Mortality Score was also assessed in a sub-cohort of patients.

Findings: In 2,387 participants, the overall mortality was 18%. In all scores examined, increasing score was associated with increased risk of ESAE. Area under the curve (AUC) to predict ESAE for CURB65, qSOFA, Lac-CURB65, MuLBSTA and NEWS2 were 0.61, 0.62, 0.59, 0.59 and 0.68, respectively. AUC to predict ESAE was 0.60 with ISARIC 4C Mortality Score.

Conclusion: None of the scores examined accurately predicted ESAE in SARS-CoV-2 infection. Non-validated scores should not be used to inform clinical decision making in COVID-19.

Keywords: COVID-19; collaborative; pneumonia; severity score.

Fig 1.

Modified consort diagram demonstrating inclusion of cases. For a detailed overview of missing data, see supplementary material S1, Table S1. CURB65 = confusion, urea nitrogen, respiratory rate, blood pressure and age of 65 years or older score; Lac-CURB65 = lactate, confusion, urea nitrogen, respiratory rate, blood pressure and age of 65 years or older score; MuLBSTA = multilobular infiltration, hypo-lymphocytosis, bacterial coinfection, smoking history, hyper-tension and age score; NEWS2 = National Early Warning Score 2; qSOFA = quick Sequential (Sepsis-related) Organ Failure Assessment; RT-PCR = reverse transcription – polymerase chain reaction.

Fig 2.

Receiver operator curve for early severe adverse event in all SARS-CoV-2 infection. CURB65 = confusion, urea nitrogen, respiratory rate, blood pressure and age of 65 years or older score; Lac-CURB65 = lactate, confusion, urea nitrogen, respiratory rate, blood pressure and age of 65 years or older score; MuLBSTA = multilobular infiltration, hypo-lymphocytosis, bacterial coinfection, smoking history, hyper-tension and age score; NEWS2 = National Early Warning Score 2; qSOFA = quick Sequential (Sepsis-related) Organ Failure Assessment; ROC = area under the receiver operator curve.

Fig 3.

Receiver operator curve for early severe adverse event in COVID-19-associated community-acquired pneumonia only. CURB65 = confusion, urea nitrogen, respiratory rate, blood pressure and age of 65 years or older score; Lac-CURB65 = lactate, confusion, urea nitrogen, respiratory rate, blood pressure and age of 65 years or older score; MuLBSTA = multilobular infiltration, hypo-lymphocytosis, bacterial coinfection, smoking history, hyper-tension and age score; NEWS2 = National Early Warning Score 2; qSOFA = quick Sequential (Sepsis-related) Organ Failure Assessment; ROC = area under the receiver operator curve.