Clinical performance of rapid antigen tests in comparison to RT‐PCR for SARS‐COV‐2 diagnosis in Omicron variant: A systematic review and meta‐analysis

Abstract The Omicron variant of concern has a high level of mutations in different genes that has raised awareness about the performance of immunological products such as vaccines and antigen detection kits. In this systematic review and meta‐analysis, we investigated whether Omicron had a significant influence on rapid antigen test (RAT) performance in comparison to PCR. We registered this systematic review and meta‐analysis in PROSPERO with the registration number CRD42022355510. We searched PubMed, Scopus, Embase, and Web of Science databases systematically to 1 August 2022. After article screening, we assessed the quality of the included studies based on the JBI checklist. Following data extraction, we performed a meta‐analysis using R software. We included 18 qualified articles presenting sufficient data about RATs performance in comparison to RT‐PCR in Omicron infections. The pooled specificity and sensitivity of RATs were 1.000 (0.997–1.000) and 0.671 (0.595–0.721), respectively. The FDA‐approved kits showed a better performance than WHO‐approved ones with a sensitivity of 0.728 (0.620–0.815). The use of RATs with nasal swabs showed a higher sensitivity compared with nasopharyngeal swabs. The sensitivity for samples with a CT‐value >25 was 0.108 (0.048–0.227). Rapid antigen tests show impaired performance for COVID‐19 diagnosis when the Omicron variant is circulating, particularly in samples with low viral loads.