Evaluation of Reliability and Validity of the RALE and BRIXIA Chest-X Ray Scores in Patients Hospitalized with COVID-19 Pneumonia.

Introduction: Chest X-rays are commonly used to assess the severity in patients that present in the emergency department with suspected COVID-19 pneumonia, but in clinical practice quantitative scales are rarely employed.

Aims: To evaluate the reliability and validity of two semi-quantitative radiological scales in patients hospitalized for COVID-19 pneumonia (BRIXIA score and RALE score).

Methods: Patients hospitalized between October 2021 and March 2022 with confirmed COVID-19 pneumonia diagnosis were eligible for inclusion. All included patients had a chest X-ray taken in the ED before admission. Three raters that participated in the treatment and management of patients with COVID-19 during the pandemic independently assessed chest X-rays.

Results: Intraclass coefficients for BRIXΙA and RALES was 0.781 (0.729-0.826) and 0.825 (0.781-0.862) respectively, showing good to excellent reliability overall. Pairwise analysis was performed using quadratic weighted kappa showing significant variability in the inter-rater agreement. The prognostic accuracy of the two scores for in-hospital mortality for all raters was between 0.753 and 0.763 for BRIXIA and 0.737 and 0.790 for RALES, demonstrating good to excellent prognostic value. Both radiological scores were significantly associated with inhospital mortality after adjustment for 4C Mortality score. We found a consistent upwards trend with significant differences between severity groups in both radiological scores.

Conclusion: Our findings suggest that BRIXIA and RALES are reliable and can be used to assess the prognosis of patients with COVID-19 requiring hospitalization. However, the inherent subjectivity of radiological scores might make it difficult to set a cut-off value suitable for all assessors.