Which role for chest x-ray score in predicting the outcome in COVID-19 pneumonia?

OBJECTIVE: We aim to demonstrate that a chest X-ray (CXR) scoring system for COVID-19 patients correlates with patient outcome and has a prognostic value. METHODS: This retrospective study included CXRs of COVID-19 patients that reported the Brixia score, a semi-quantitative scoring system rating lung involvement from 0 to 18. The highest (H) and lowest (L) values were registered along with scores on admission (A) and end of hospitalization (E). The Brixia score was correlated with the outcome (death or discharge). RESULTS: A total of 953 patients met inclusion criteria. In total, 677/953 were discharged and 276/953 died during hospitalization. A total of 524/953 had one CXR and 429/953 had more than one CXR. H-score was significantly higher in deceased (median, 12; IQR 9–14) compared to that in discharged patients (median, 8; IQR 5–11) (p < 0.0001). In 429/953 patients with multiple CXR, A-score, L-score, and E-score were higher in deceased than in discharged patients (A-score 9 vs 8; p = 0.039; L-score 7 vs 5; p < 0.0003; E-score 12 vs 7; p < 0.0001). In the entire cohort, logistic regression showed a significant predictive value for age (p < 0.0001, OR 1.13), H-score (p < 0.0001, OR 1.25), and gender (p = 0.01, male OR 1.67). AUC was 0.863. In patients with ≥ 2 CXR, A-, L-, and E-scores correlated significantly with the outcome. Cox proportional hazards regression indicated age (p < 0.0001, HR 4.17), H-score (< 9, HR 0.36, p = 0.0012), and worsening of H-score vs A score > 3 (HR 1.57, p = 0.0227) as associated with worse outcome. CONCLUSIONS: The Brixia score correlates strongly with disease severity and outcome; it may support the clinical decision-making, particularly in patients with moderate-to-severe signs and symptoms. The Brixia score should be incorporated in a prognostic model, which would be desirable, particularly in resource-constraint scenarios. KEY POINTS: • To demonstrate the importance of the Brixia score in assessing and monitoring COVID-19 lung involvement. • The Brixia score strongly correlates with patient outcome and can be easily implemented in the routine reporting of CXR.