Molecular diagnostic for SARS-CoV-2: an experimental External Quality Assessment Scheme

ABSTRACT

Introduction: external Quality Assessment (EQA) is a valuable tool to monitor and improve the analytical performances of clinical laboratories. To guarantee suitable results also during the COVID-19 pandemic, EQA scheme providers have implemented specific schemes assessing different SARS-CoV-2 diagnostic systems. This study aims to describe the results collected in an experimental EQA scheme for molecular diagnostic of SARS-CoV-2 managed by INSTAND eV with the collaboration of the Centre of Biomedical Research for Quality in Laboratory Medicine for Veneto Region Laboratories. Methods: the qualitative EQA results collected in three surveys (two in 2020 and one in 2021) for 18 samples total, have been summarized to identify the percentage of laboratory results per sample. Control samples were provided by NationalesKonsiliarlaboratorium fur Coronaviren of Berlin. Results: even though the average of the participating laboratories strongly decreased between surveys, a good agreement was found among results (95% to 99.8%). A totally of 0.2% - 4% of incorrect results and 0% - 1.1% of indeterminate results were reported. In addition, the sequencing analysis and the point mutations analysis, included in the last analyzed survey, revealed a good agreement between participating laboratories with an overall score from 74.8% to 89.6% for the sequencing and from 90.65% to 95.33% for the point mutations, respectively. Conclusions: the EQA programs are a fundamental quality assurance tool to evaluate the laboratory performance and to appreciate the State-of-the-Art of the different diagnostic systems used by participating laboratories. The need for an EQA scheme for every test performed in the laboratory is mandatory to guarantee patient safety.