Ensuring diagnostic testing accuracy for patient care and public health- COVID-19 testing scale-up from an EQA provider's perspective

Veronica Restelli; Selvarani Vimalanathan; Mahfuza Sreya; Michael A Noble; Lucy A Perrone

doi:10.1371/journal.pgph.0001615

Ensuring diagnostic testing accuracy for patient care and public health- COVID-19 testing scale-up from an EQA provider's perspective

PLOS Glob Public Health. 2023 Dec 6;3(12):e0001615. doi: 10.1371/journal.pgph.0001615. eCollection 2023.

Authors

Veronica Restelli¹, Selvarani Vimalanathan¹, Mahfuza Sreya¹, Michael A Noble¹, Lucy A Perrone¹

Affiliation

¹ Canadian Microbiology Proficiency Testing Program (CMPT), Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, British Columbia, Canada.

Abstract

In response to the coronavirus pandemic (COVID-19) and scale up of diagnostic testing, the Canadian Microbiology Proficiency Testing program created a new proficiency testing (PT) program for the molecular and antigen detection of SARS-CoV-2. The program was geared to point of care testing (POCT) sites located in each of the eight provincial Health Authorities across British Columbia, Canada, with the intention to monitor testing quality. The PT program consisted of 6 shipments in a year, each containing a set of 4 samples either positive for SARS-CoV-2 virus or negative. The program began with initial 23 sites enrolling in March 2021, expanding to >100 participants by December 2021. After the first two surveys, it was observed that testing performance (accuracy) was consistently acceptable for sites using nucleic acid technology (NAT), however performance by sites using rapid antigen detection (RAD) methods was poor, especially when testing the weakly positive samples. A root cause investigation of poor testing performance revealed gaps in the execution of testing methods and also in results interpretation. These quality issues were most commonly associated with new testers who lacked experience with diagnostic testing. Tester training and mentoring was reinforced as was retraining of personnel; sample processing instructions were modified, and a training video was also created for testing sites. As a result of these interventions, sites improved their testing accuracy and the performance of POCT sites using RAD methods came to more closely match the performance of sites utilizing NAT. Overall, the PT program was highly successfully and improved quality of testing in the province. This work demonstrates the critical value of an external quality assessment (EQA) partner towards improving patient and public health and safety, especially when testing is conducted outside of an accredited medical laboratory setting.

Copyright: © 2023 Restelli et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Grants and funding

Funding for this work was provided through a fee for service mechanism established at the CMPT program at UBC. LAP holds the Rix Professorship of Laboratory Quality at the University of British Columbia and receives financial support from the Donald B. Rix Family Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.