Effectiveness and user experience of nose and throat swabbing techniques for SARS-CoV-2 detection: results from the UK COVID-19 National Testing Programme.

Abstract

Background: The UK's National Health Service Test and Trace (NHSTT) program aimed to provide the most effective and accessible SARS-CoV-2 testing approach possible. Early user feedback indicated that there were accessibility issues associated with throat swabbing. We report the results of service evaluations performed by NHSTT to assess the effectiveness and user acceptance of swabbing approaches, as well as qualitative findings of user experiences from research reports, surveys, and incident reports. Our intent is to present and summarize our findings about the application of alternative swabbing approaches during the COVID-19 pandemic in the UK.

Methods: From May 2020 to December 2021, NHSTT conducted a series of service evaluations assessing self-swabbing and assisted swabbing of the nose and throat, and nose only (anterior nares/mid-turbinate) using polymerase chain reaction (PCR) and lateral flow devices (LFDs), for diagnostic suitability within the COVID-19 National Testing Programme. Outcomes included observational user feedback on swabbing approaches and quantitative testing performance (concordance, sensitivity, and specificity). A post-hoc indirect comparison of swabbing approaches was also performed. Additionally, an analysis of existing cross-service research was conducted in April 2021 to determine user feedback regarding swabbing approaches.

Results: Observational data from cross-service research indicated a user preference for nose swabbing over throat swabbing. Significantly more users reported that nose swabbing was easier to perform than throat swabbing (50% vs. 12%) and there were significantly fewer reported incidents. In the service evaluations, while there was reduced sensitivity for nose-only swabbing for PCR (88%) compared with nose and throat swabbing, similar sensitivities were observed for nose-only and nose and throat swabbing for LFDs. The sensitivity of nose-only swabbing for LFDs was higher for individuals with higher viral concentrations.

Conclusions: User experience analyses supported a preference for nose-only swabbing. Nose-only swabbing for LFDs provided sufficient diagnostic accuracy, supporting its use as a viable option in the COVID-19 National Testing Programme. Less invasive swabbing approaches are important to maximize testing accessibility and alongside other behavioral interventions, increase user uptake.