Current best evidence for clinical care (more info)
OBJECTIVES: We aimed to evaluate the accuracy of the Panbio™ 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™ 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™ Ag-RDT in asymptomatic individuals.
|Discipline / Specialty Area||Score|
|Family Medicine (FM)/General Practice (GP)||
|General Internal Medicine-Primary Care(US)||
Unsurprisingly, there are a lot of data emerging on this topic, so practice needs to be based on frequently updated evidence synthesis, rather than individual studies.
This is a well designed and reported study on newer generation antigen tests. Like the rapid strep screen, this test is most helpful if the patient is symptomatic and the test is positive. There is still a significant risk of patients having a negative test but still having COVID-19, especially if minimally or asymptomatic.
If the test is approved for use in USA, if it is CLIA waived, and if insurance reimbursement is adequate, then this article would have relevance to US primary care providers. What we really need is a widely available, inexpensive, accurate, saliva based test for home use.
This well-designed study shows that in a primary care setting with ~10% prevalence of people testing positive for COVID acutely, this rapid antigen test had moderate sensitivity and excellent specificity.
Our hospitals in Sri Lanka are using the Antigen test to screen patients prior to admission. Therefore this study will add to the knowledge base of the health system and enable to fine-tune the screening process.