Thoracic Research and Practice
Original Article

Chest-X-ray-Based Scoring, Total Leukocyte Count, and Neutrophil-to-Lymphocyte Ratio for Prediction of COVID-19 in Patients with Severe Acute Respiratory Illness

1.

Department of Diagnostic and Interventional Radiology, All India Institute of Medical Sciences, Jodhpur, India

2.

Department of General Medicine, All India Institute of Medical Sciences, Jodhpur, India

3.

Department of Microbiology, All India Institute of Medical Sciences, Jodhpur, India

4.

Department of Pathology and Lab medicine, All India Institute of Medical Sciences, Jodhpur, India

5.

Department of Pulmonary Medicine, All India Institute of Medical Sciences, Jodhpur, India

6.

Department of Pharmacology, All India Institute of Medical Sciences, Jodhpur, India

7.

Department of Surgical Oncology, All India Institute of Medical Sciences, Jodhpur, India

Thorac Res Pract 2021; 22: 130-136
DOI: 10.5152/TurkThoracJ.2021.20239
Read: 970 Downloads: 429 Published: 01 March 2021

OBJECTIVE: This study aimed to use chest-X-ray (CXR)-based scores along with total leukocyte count (TLC) and neutrophil-to-lymphocyte ratio (NLR) in the prediction of coronavirus disease 2019 (COVID-19) in patients presenting with clinical features of severe acute respiratory illness (SARI).

MATERIAL AND METHODS: This is a retrospective study involving all patients who presented with clinical features of SARI and who had undergone bedside chest X-ray (CXR), hemograms with TLC, NLR, and reverse transcriptase-polymerase chain reaction (RT-PCR) at our institute from May 1 to June 30, 2020.

RESULTS: Of 204 patients, 115 tested RT-PCR-positive and 89 tested negative. The patients who presented with SARI, using CXR-based score of 4 or more, TLC of less than 8,700 cells/μL, and NLR of <7 had a statistically significant area under the curve (p<0.001) for diagnosing COVID-19. The sensitivity and specificity of the CXR score was 80.8% and 73.0%, of TLC was 70.1% and 74.7%, and of NLR was 70.1% and 59.0%, respectively, in diagnosing COVID-19 alone. The specificity further increased to 90.4% when we used the CXR score with NLR and to 92.8% when we used the CXR score with TLC. The post-test odds (“rule in” disease) of a positive test for having the disease were 3, 2.77, and 1.71 times with the use of either CXR score, TLC, or NLR criteria, respectively; whereas, combined use of CXR score and NLR increased the post-test odds by 5.53 times, and combination of CXR score with TLC increased the post-test odds by 7.5 times. 

CONCLUSION: CXR score with TLC and NLR can predict COVID-19 infection among those who presented with features of SARI. This may help in the early isolation of the patient until the RT-PCR report becomes available. 

Cite this article as: Garg PK, Khera PS, Saxena S, et al. Chest-X-ray-based scoring, total leukocyte count, and neutrophil-to-lymphocyte ratio for prediction of COVID-19 in patients with severe acute respiratory illness. Turk Thorac J 2021; 22(2): 130-6.

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