AbstractObjectivesTo evaluate the inter-rater agreement of chest X-ray (CXR) findings in coronavirus disease 2019 (COVID-19) and to determine the value of initial CXR along with demographic, clinical, and laboratory data at emergency department (ED) presentation for predicting mortality and the need for ventilatory support.MethodsA total of 340 COVID-19 patients who underwent CXR in the ED setting (March 1–13, 2020) were retrospectively included. Two reviewers independently assessed CXR abnormalities, including ground-glass opacities (GGOs) and consolidation. Two scoring systems (Brixiascore and percentage of lung involvement) were applied. Inter-rater agreement was assessed by weighted Cohen’s kappa (κ) or intraclass correlation coefficient (ICC). Predictors of death and respiratory support were identified by logistic or Poisson regression.ResultsGGO admixed with consolidation (n= 235, 69%) was the most common CXR finding. The inter-rater agreement was almost perfect for type of parenchymal opacity (κ= 0.90),Brixiascore (ICC = 0.91), and percentage of lung involvement (ICC = 0.95). TheBrixiascore (OR: 1.19; 95% CI: 1.06, 1.34;p= 0.003), age (OR: 1.16; 95% CI: 1.11, 1.22;p< 0.001), PaO₂/FiO₂ratio (OR: 0.99; 95% CI: 0.98, 1;p= 0.002), and cardiovascular diseases (OR: 3.21; 95% CI: 1.28, 8.39;p= 0.014) predicted death. Percentage of lung involvement (OR: 1.02; 95% CI: 1.01, 1.03;p= 0.001) and PaO₂/FiO₂ratio (OR: 0.99; 95% CI: 0.99, 1.00;p< 0.001) were significant predictors of the need for ventilatory support.ConclusionsCXR is a reproducible tool for assessing COVID-19 and integrates with patient history, PaO₂/FiO₂ratio, and SpO₂values to early predict mortality and the need for ventilatory support.Key Points• Chest X-ray is a reproducible tool for assessing COVID-19 pneumonia.•The Brixia score and percentage of lung involvement on chest X-ray integrate with patient history, PaO₂/FIO₂ratio, and SpO₂values to early predict mortality and the need for ventilatory support in COVID-19 patients presenting to the emergency department.