ABSTRACT
INTRODUCTION: Diagnosis of COVID-19 is through polymerase chain reaction (PCR) or typical involvement of the lung by the virus in computed tomography (CT) scan. However, PCR is not always available, and also CT scan has a high dose of radiation. This study was performed to find the role of complete blood cell (CBC) indices and qualitative C-reactive protein (CRP) in screening of symptomatic patients. MATERIAL AND METHODS: A diagnostic accuracy study was performed on symptomatic cases in Abadan. Four stepwise logistic regression models were designed that the outcomes were PCR positivity, CT scan positivity, PCR and CT scan positivity, and COVID-19 positivity (i.e., PCR or CT scan positivity). Post-estimation receiver operating characteristics (ROC) curve analysis was performed to report the area under the curve (AUC). RESULTS: A total of 104 patients were studied. The most accurate model was for the prediction of CT scan positivity (AUC = 0.874) in which the predictors were age [odds ratio (OR) =1.063] and CRP (OR = 2.661 for each plus of positivity). The second accurate model was for the prediction of COVID-19 positivity (AUC = 0.828) in which the predictors were white blood cell count (OR = 0.735 for every 1000 counts per μL) and neutrophil per lymphocyte ratio (OR = 1.248). CONCLUSIONS: Higher levels of CRP are associated with and predictor of lung involvement in COVID-19 infection. CRP qualitative levels can be measured before a CT scan if there is no other indication for imaging. © 2022 Via Medica.