EVALUATION OF THE DIAGNOSTIC PERFORMANCE OF COVID-19 RAPID ANTIGEN TEST IN COMPARISON TO SARS-COV-2 REVERSE TRANSCRIPTASE POLYMERASE CHAIN REACTION

Objective: The World Health Organization recommends reverse transcriptase polymerase chain reaction (RT-PCR) as the reference method for COVID-19 diagnosis. However, it is time- consuming, costly, and requires specialized equipment and trained personnel. Therefore, rapid antigen tests (RATs), which provide results within 15–30 minutes, have emerged as a potential alternative. The aim of the current study was to assess the diagnostic performance of the SARS-CoV-2 Rapid Antigen Test (Ref No: 9901-NCOV-01G, Roche Diagnostics) compared to RT-PCR in adult patients with COVID-19-related symptoms. Material and Methods: In this prospective observational study, 492 symptomatic adult patients, aged ≥ 18 years, were tested using simultaneous oro-nasopharyngeal swabs for RAT and RT- PCR. Diagnostic metrics were calculated, and the impact of cycle threshold (Ct) values and symptom duration on RAT performance was analyzed. Results: In total, 167 (33.9%) of 492 patients’ oro- nasopharyngeal swab samples tested by RT-PCR result were positive. Compared to RT-PCR, the sensitivity, specificity, positive and negative predictive value of RAT were 90.4% [95% confidence interval (CI): 85%-94%], 98.8% (95% CI: 96.9%-99.5%), 97.4% (95% CI: 93.6%-99%) and 95.3% (95% CI: 92.4%-97.1%), respectively. The Ct values of samples with false-negative RAT results were higher than the samples that tested positive by RAT and RT-PCR [23.93±4.40) vs. 18.42±4.56), p