A multicenter study to assess the performance of the point-of-care RT-PCR Cobas SARS-2 CoV-2 & Influenza A/B nucleic acid test for use on the Cobas Liat system in comparison with 3 centralized assays across healthcare facilities in the United States

Abstract

Respiratory diseases can share many of the same symptoms, highlighting the need for timely and accurate differentiation to facilitate effective clinical management and reduce transmission. Compared with centralized testing, molecular point-of-care tests (POCT) can provide a faster time to result. We evaluated the RT-PCR POCT Cobas® SARS-CoV-2 & Influenza A/B qualitative assay for use on the Cobas Liat® system (the Cobas Liat SARS-CoV-2 & Influenza A/B test) in nasal and nasopharyngeal swab samples from 10 diverse healthcare facilities in the US. A composite comparator design consisting of three centralized tests was used to analyze SARS-CoV-2, whilst performance versus a single centralized test was used for analysis of influenza A and B. Evaluations included performance stratified by sample type (prospective/retrospective and nasal/nasopharyngeal [paired by subject]), collection method (self/healthcare worker-collected [alternated and approximately balanced], symptom status (symptomatic/asymptomatic), and SARS-CoV-2 vaccination status, as well as assay inclusivity and system ease of use. A total of 2,247 samples were tested. For SARS-CoV-2, the overall percent agreement (OPA) was 98.8% (95% CI: 97.9, 99.3) in nasal swab samples and 99.0% (95% CI: 98.2, 99.4) in nasopharyngeal swab samples. Regression analysis showed that Ct values from paired nasal and nasopharyngeal swab samples were highly correlated (correlation coefficient 0.83). The OPA was ≥99.5% (sample type dependent) and 100.0% for influenza A and B, respectively. The Cobas Liat SARS-CoV-2 & Influenza A/B test was easy to use. These results support the use of the POCT in various sample types and by various operators in the intended-use setting.