Evaluation of the diagnostic accuracy of COVID-19 antigen tests: A systematic review and meta-analysis

Background The coronavirus disease 2019 (COVID-19) pandemic continues to affect countries worldwide. To inhibit the transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), testing of patients, contact tracing, and quarantine of their close contacts have been used as major non-pharmaceutical interventions. The advantages of antigen tests, such as low cost and rapid turnaround, may allow for the rapid identification of larger numbers of infectious persons. This meta-analysis aimed to evaluate the diagnostic accuracy of antigen tests for SARS-CoV-2. Methods We searched PubMed, Embase, Cochrane Library, and Biomed Central databases from inception to January 2, 2021. Studies evaluating the diagnostic accuracy of antigen testing for SARS-CoV-2 with reference standards were included. We included studies that provided sufficient data to construct a 2 × 2 table on a per-patient basis. Only articles in English were reviewed. Summary sensitivity and specificity for antigen tests were generated using a random-effects model. Results Fourteen studies with 8,624 participants were included. The meta-analysis for antigen testing generated a pooled sensitivity of 79% (95% CI: 66-88%; 14 studies, 8,624 patients) and a pooled specificity of 100% (95% CI: 99-100%; 14 studies, 8,624 patients). The subgroup analysis of studies that reported specimen collection within 7 days after symptom onset showed a pooled sensitivity of 95% (95% CI: 78-99%; 4 studies, 1,342 patients) and pooled specificity of 100% (95% CI: 97-100%; 4 studies, 1,342 patients). Regarding the applicability, the patient selection, index tests, and reference standards of studies in our meta-analysis matched the review title. Conclusion Antigen tests have moderate sensitivity and high specificity for the detection of SARS-CoV-2. Antigen tests might have a higher sensitivity in detecting SARS-CoV-2 within 7 days after symptom onset. Based on our findings, antigen testing might be an effective method for identifying contagious individuals to block SARS-CoV-2 transmission.