A novel chest CT severity score in COVID-19 and its correlation with severity and prognosis of the lung disease: A retrospective cohort study

BACKGROUND: HRCT chest has a high sensitivity in the diagnosis of patients with COVID-19 infection. Through our study, we intend to evaluate the diagnostic accuracy and inter-reader variability of a semi-quantitative CT severity score, a novel parameter designed for risk stratification and prognostication of COVID-19 pneumonia with clinical staging of disease. METHODS: It was a single-center retrospective analysis performed on an original cohort of 4180 symptomatic patients with the suspicion of SARS-CoV-2 interstitial pneumonia. Out of 4180, a total of 4004 patients with COVID-19 were confirmed by an RT-PCR. We used an HRCT chest severity score (CT-SS) to evaluate the COVID-19 disease burden on the initial scan obtained at admission. The data were analyzed with IBM SPSS Statistics Version 22.0 Release 2013. RESULTS: Our study subjects demonstrated the most common clinical features fever, cough, dyspnea, and body aches. Raised CRP levels (CRP >0.5 mg/dL) were found in 81.86% and increased D-dimer levels (>500 ng/mL) were found in 92.3% of patients. The most common radiological findings of the disease included ground-glass opacities, observed in 98.8%. Our study has a sensitivity of 89.2%, a specificity of 94.8%, a positive predictive value (PPV) of 90.6%, and a negative predictive value (NPV) of 94%. CONCLUSION: As per our findings, this novel CT scoring system might aid in the risk stratification and the short-term prognostication of patients suffering from COVID-19 pneumonia. This will eventually help in curtailing the extensive burden on the healthcare system amid the current pandemic.