A simple chest CT score for assessing the severity of pulmonary involvement in COVID-19

BACKGROUND: A major role of CT in COVID-19 pneumonia is to assess disease severity and progress. In this study, we aimed to assess the validity, reliability, and survival outcomes of simple chest computed tomography (CT) score in the evaluation of the severity of lung involvement in coronavirus disease 2019 (COVID-19) compared with the current chest CT score. RESULTS: This retrospective analysis included 213 patients (121 men and 92 women; mean age, 46 ± 15.6 years; range, 1–85 years). The ROC curve was used to compare the validity of both scores. Interreader agreement (IRA) for both scores was calculated using Cohen’s kappa statistic. The survival analysis of both scores was investigated using the Kaplan–Meier survival analysis. The simple score showed a comparable validity with the current score (AUC = 0.89 and 0.90, respectively; p = 0.61). The ROC analysis demonstrated that a simple score of > 3 and a current score of > 12 were potential predictors of death with sensitivity values of 81.8% and 86.4% and specificity values of 96.3% and 93.7%, respectively. The simple score showed a higher IRA compared with the current score (κ = 0.645 and 0.458, respectively). Both scores were comparable for predicting survival outcomes. CONCLUSION: The simple score was non-inferior for predicting survival outcome, compared with the current chest CT score. Furthermore, we suggest that the simple score should be used as it is simpler and more consistent.