COVID-19 Evidence Alerts
from McMaster PLUSTM

Current best evidence for clinical care (more info)

COVID-19 Evidence Alerts needs your support. If our service is of value to you, please consider donating to keep it going. Learn more Donate now

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.

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.

Discipline / Specialty Area Score
Hospital Doctor/Hospitalists
Internal Medicine
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.