Panbio™ rapid antigen test for SARS-CoV-2 has acceptable accuracy in symptomatic patients in primary health care

Abstract

Objectives: We aimed to evaluate the accuracy of the Panbio (TM) Ag-RDT at primary health care (PHC) centers and test sites in symptomatic patients and close contacts, using the Reverse-Transcription Polymerase Chain Reaction (RT-PCR) test as the gold standard. Methods: The study was conducted in four PHC centers and two test sites in Mallorca, Spain. Consecutive patients older than 18 years, attending the sites for RT-PCR testing were included. Two nasopharyngeal samples were collected, one for RT-PCR and the other was processed on-site using the Panbio (TM) rapid antigen test kit for SARS-CoV-2. The sensitivity and specificity were calculated using RT-PCR as the reference, and the predictive values using the pretest probability results for each analyzed group. Findings: A total of 1369 participants were included; mean age 42.5 +/- 14.9 years and 54.3% women. The overall prevalence was 10.2%. Most participants (70.6%) presented within 5 days of the onset of symptoms. The overall sensitivity was of 71.4% (95% CI: 63.1%, 78.7%), the specificity of 99.8% (95% CI: 99.4%, 99.9%), the positive predictive value of 98.0% (95% CI: 93.0%, 99.7%) and a negative predictive value of 96.8% (95% CI: 95.7%, 97.7%). The sensitivity was higher in symptomatic patients, in those arriving within 5 days since symptom onset and in those with high viral load. Interpretation: Ag-RDT had relatively good performance characteristics in suspected symptomatic patients within five days since the onset of symptoms. However, our data do not support the sole use of Panbio (TM) Ag-RDT in asymptomatic individuals. Funding: None (C) 2021 The Author(s). Published by Elsevier Ltd on behalf of The British Infection Association.