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Chest Radiograph Scoring Alone or Combined with Other Risk Scores for Predicting Outcomes in COVID-19

Au-Yong, Iain; Higashi, Yutaro; Giannotti, Elisabetta; Fogarty, Andrew; Morling, Joanne R.; Grainge, Matthew; Race, Andrea; Juurlink, Irene; Simmonds, Mark; Briggs, Steve; Crooks, Colin J.; Cruikshank, Simon; Hammond-Pears, Susan; West, Joe; Card, Timothy


Iain Au-Yong

Yutaro Higashi

Elisabetta Giannotti

Clinical Associate Professor & Reader in Clinical Epidemiology

Andrea Race

Irene Juurlink

Mark Simmonds

Steve Briggs

Simon Cruikshank

Susan Hammond-Pears

Professor of Epidemiology

Clinical Associate Professor


Background Radiographic severity may help predict patient deterioration and outcomes from COVID-19 pneumonia. Purpose To assess the reliability and reproducibility of three chest radiograph reporting systems (radiographic assessment of lung edema [RALE], Brixia, and percentage opacification) in patients with proven SARS-CoV-2 infection and examine the ability of these scores to predict adverse outcomes both alone and in conjunction with two clinical scoring systems, National Early Warning Score 2 (NEWS2) and International Severe Acute Respiratory and Emerging Infection Consortium: Coronavirus Clinical Characterization Consortium (ISARIC-4C) mortality. Materials and Methods This retrospective cohort study used routinely collected clinical data of patients with polymerase chain reaction-positive SARS-CoV-2 infection admitted to a single center from February 2020 through July 2020. Initial chest radiographs were scored for RALE, Brixia, and percentage opacification by one of three radiologists. Intra- and interreader agreement were assessed with intraclass correlation coefficients. The rate of admission to the intensive care unit (ICU) or death up to 60 days after scored chest radiograph was estimated. NEWS2 and ISARIC-4C mortality at hospital admission were calculated. Daily risk for admission to ICU or death was modeled with Cox proportional hazards models that incorporated the chest radiograph scores adjusted for NEWS2 or ISARIC-4C mortality. Results Admission chest radiographs of 50 patients (mean age, 74 years ± 16 [standard deviation]; 28 men) were scored by all three radiologists, with good interreader reliability for all scores, as follows: intraclass correlation coefficients were 0.87 for RALE (95% CI: 0.80, 0.92), 0.86 for Brixia (95% CI: 0.76, 0.92), and 0.72 for percentage opacification (95% CI: 0.48, 0.85). Of 751 patients with a chest radiograph, those with greater than 75% opacification had a median time to ICU admission or death of just 1-2 days. Among 628 patients for whom data were available (median age, 76 years [interquartile range, 61-84 years]; 344 men), opacification of 51%-75% increased risk for ICU admission or death by twofold (hazard ratio, 2.2; 95% CI: 1.6, 2.8), and opacification greater than 75% increased ICU risk by fourfold (hazard ratio, 4.0; 95% CI: 3.4, 4.7) compared with opacification of 0%-25%, when adjusted for NEWS2 score. Conclusion Brixia, radiographic assessment of lung edema, and percentage opacification scores all reliably helped predict adverse outcomes in SARS-CoV-2 infection. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Little in this issue.


Au-Yong, I., Higashi, Y., Giannotti, E., Fogarty, A., Morling, J. R., Grainge, M., …Card, T. (2022). Chest Radiograph Scoring Alone or Combined with Other Risk Scores for Predicting Outcomes in COVID-19. Radiology, 302(2), 460-469.

Journal Article Type Article
Acceptance Date Aug 16, 2021
Online Publication Date Sep 14, 2021
Publication Date Feb 1, 2022
Deposit Date Sep 22, 2021
Publicly Available Date Mar 15, 2022
Journal Radiology
Print ISSN 0033-8419
Electronic ISSN 1527-1315
Publisher Radiological Society of North America
Peer Reviewed Peer Reviewed
Volume 302
Issue 2
Pages 460-469
Keywords Radiology, chest radiograph scoring, risk scores, predicting outcomes, COVID-19
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