Role of Modified RALES and Brixia Scores Section in Predicting the COVID-19 Positivity among the Suspected Patients: A Cross-sectional Observational Study
Authors: Sinha Nitin , Jalan Divesh , Jain Princi 
Published: March 2022

Introduction: Computed Tomography (CT) chest plays an important role in triaging and managing patients of suspected COVID-19, especially in those where Coronavirus Disease 2019 (COVID-19) report is pending but CT chest has constraints of availability and cost. Chest X-ray (CXR) is a readily available investigation and is cheaper than a CT chest. Hence, any scoring on CXR which proves to be helpful in triaging and managing suspected COVID19 patients will alleviate the dependency on CT chest. Modified Radiographic Assessment of Lung Edema Score (mRALES) and Brixia scores have been used to assess severity of disease and prognosis in COVID-19 confirmed cases. However, these two scores have never been used as a method to predict the confirmed COVID-19 pateints among the the suspected COVID-19 cases. Aim: To evaluate the role of mRALES and Brixia score along with clinical and laboratory parameters in predicting confirmed positive cases among suspected COVID-19 patients. Materials and Methods: This retrospective cross-sectional, observational study was conducted in Department of Medicine at Atal Bihari Vajpayee Institute of Medical Sciences (ABVIMS) and Dr. Ram Manohar Lohia Hospital, New Delhi, India, from 1st to 15th December 2020. Case records of patients admitted with severe acute respiratory illness (suspected COVID-19) were accessed and used to fill up a proforma where clinical and laboratory parameters were recorded. Chest radiographs (posteroanterior and anteroposterior) of the patients were evaluated to calculate mRALES and Brixia scores. Sensitivity, specificity, positive preditive value and negative predictive value were calculated. The p-value <0.05 was considered as statistically significant. Results: Out of the 113 patients, 62 were males and 51 females. The COVID-19 positivity rate was 15.04% (n=17). Mean age of patients was 52.64±15.63 years. Overall, the mean mRALES and Brixia scores were not statistically different between suspected (mRALES=3.94±2.51, Brixia=7.29±4.642), and confirmed COVID19 (mRALES=4.25±2.56, Brixia=7.73±4.84) patients. However, in the subgroup of patients with history of obstructive airway disease, Brixia score was significantly higher among COVID-19 positive patients (7.09±4.70) as compared to COVID-19 suspected patients (0.53±4.31). Presence of low TLC {<9550/mm3 with sensitivity of 70.62%, specificity of 67.3%, Positive Predictive Value (PPV) of 26.7% and Negative Predictive Value (NPV) of 92.4%} and low ANC {< 7580/mm3 with sensitivity of 64.7%, specificity of 63.2%, PPV of 22.9% and NPV of 90.5%} significantly predicted the COVID-19 positivity among the suspected COVID-19 patients. Conclusion: mRALES and Brixia scores on CXR are not significantly different between suspected and confirmed COVID-19 patients and hence, cannot be used to judge who among suspected COVID-19 patients will turn out to be COVID-19 positive later. However, a TLC of less than 9550/ mm3 and an ANC of less than 7580/mm3 can predict COVID-19 positivity among suspected patients.