COVID-19 Evidence Alerts
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Diagnosis Lieveld AWE, Azijli K, Teunissen BP, et al. Chest CT in COVID-19 at the ED: Validation of the COVID-19 Reporting and Data System (CO-RADS) and CT Severity Score: A Prospective, Multicenter, Observational Study. Chest. 2021 Mar;159(3):1126-1135. doi: 10.1016/j.chest.2020.11.026. Epub 2020 Nov 30.
Abstract

BACKGROUND: CT is thought to play a key role in coronavirus disease 2019 (COVID-19) diagnostic workup. The possibility of comparing data across different settings depends on the systematic and reproducible manner in which the scans are analyzed and reported. The COVID-19 Reporting and Data System (CO-RADS) and the corresponding CT severity score (CTSS) introduced by the Radiological Society of the Netherlands (NVvR) attempt to do so. However, this system has not been externally validated.

RESEARCH QUESTION: We aimed to prospectively validate the CO-RADS as a COVID-19 diagnostic tool at the ED and to evaluate whether the CTSS is associated with prognosis.

STUDY DESIGN AND METHODS: We conducted a prospective, observational study in two tertiary centers in The Netherlands, between March 19 and May 28, 2020. We consecutively included 741 adult patients at the ED with suspected COVID-19, who received a chest CT and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) PCR (PCR). Diagnostic accuracy measures were calculated for CO-RADS, using PCR as reference. Logistic regression was performed for CTSS in relation to hospital admission, ICU admission, and 30-day mortality.

RESULTS: Seven hundred forty-one patients were included. We found an area under the curve (AUC) of 0.91 (CI, 0.89-0.94) for CO-RADS using PCR as reference. The optimal CO-RADS cutoff was 4, with a sensitivity of 89.4% (CI, 84.7-93.0) and specificity of 87.2% (CI, 83.9-89.9). We found a significant association between CTSS and hospital admission, ICU admission, and 30-day mortality; adjusted ORs per point increase in CTSS were 1.19 (CI, 1.09-1.28), 1.23 (1.15-1.32), 1.14 (1.07-1.22), respectively. Intraclass correlation coefficients for CO-RADS and CTSS were 0.94 (0.91-0.96) and 0.82 (0.70-0.90).

INTERPRETATION: Our findings support the use of CO-RADS and CTSS in triage, diagnosis, and management decisions for patients presenting with possible COVID-19 at the ED.

Ratings
Discipline / Specialty Area Score
Hospital Doctor/Hospitalists
Internal Medicine
Respirology/Pulmonology
Intensivist/Critical Care
Infectious Disease
Emergency Medicine
Comments from MORE raters

Emergency Medicine rater

This prospective observational study conducted in the Netherlands sought to validate The COVID-19 Reporting and Data System (CO-RADS) as a diagnostic tool in the ED and evaluate if the CT severity score (CTSS) is associated with prognosis. 741 patients were included for evaluation of CO-RADS, with RT-PCR used as gold standard for diagnosis. CO-RADS is a scoring system from 0 to 5 to classify pulmonary involvement from very unlikely to very likely. CTSS is utilized to assess disease severity and was determined in 304 patients. The authors found a CO-RADS cutoff of 4 had a sensitivity of 89% and specificity of 87%. CTSS was associated with hospital admission, ICU admissions, and 30 day mortality. While these seem promising, the gold standard was RT-PCR, which is itself associated with significant limitations. In this study, 23.8% of confirmed COVID cases had a negative initial PCR. CO-RADS was designed for those with moderate/severe symptoms and should not be used in all patients.

Infectious Disease rater

I'm not sure how much this adds to our usual use of CT to evaluate COVID-19.