Evaluation of the COVID-19 Rapid Antigen Test

Abstract

Introduction: Coronavirus disease, is an infectious disease caused by the SARS-CoV-2. The gold standard method to diagnose is the reverse transcriptase polymerase chain reaction test. Rapid antigen tests can also be used for diagnosis. This study aims to compare the results of these two methods.Materials and Methods: Between November 2021 and July 2022, the study included 1811 patients who visited the emergency depart-ment with coronavirus-related symptoms and signs. Respiratory samples from these patients were simultaneously evaluated using both reverse transcriptase polymerase chain reaction and rapid antigen tests. The reverse transcriptase polymerase chain reaction tests were conducted using the BioSpeedy SARS-CoV-2 reverse transcriptase polymerase chain reaction kit (Bioeksen-Turkiye), while the rapid antigen tests were performed using the RapidForTM SARS-CoV-2 Ag (Vitrosens-Germany).Results: The comparison of the reverse transcriptase polymerase chain reaction test and rapid antigen test results showed a 90.67% sensitivity, 98.28% specificity, 91.27% positive predictive value, 98.15% negative predictive value, and 97.02% (1757/1811) accuracy. Qualitative results of both tests exhibited a very good agreement (Kappa= 0.892, p< 0.001). According to the reverse transcriptase polymerase chain reaction test, the sensitivity of the rapid antigen test was found to be 100% in 28 samples with a cycle threshold <17, 100% in 78 samples with a cycle threshold <20, 98.33% in 120 samples with a cycle threshold <22, and 96.28% in 215 samples with a cycle threshold <25.Conclusion: When the results of the study are evaluated, it is seen that the use of the rapid antigen test for screening purposes and confirmation of patients with negative test results by Reverse transcriptase polymerase chain reaction will provide advantages in terms of both time and cost. Due to the low sensitivity and high positive predictive value of the vitrosens rapid antigen test, we think that this test can be used in the first stage to accelerate the diagnosis of patients with high viral load, who are more likely to be infectious, to prevent transmission and to start their treatment quickly.