Classification of “Near-patient” and “Point-of-Care” SARS-CoV-2 Nucleic Acid Amplification Test Systems and a first approach to evaluate their analytical independence of operator activities
Christoph Buchta, Heinz Zeichhardt, Tony Badrick, Wim Coucke, Nathalie Wojtalewicz, Andrea Griesmacher, Stephan W. Aberle, Ingo Schellenberg, Ellis Jacobs, Gunnar Nordin, Christian Schweiger, Karin Schwenoha, Peter B. Luppa, Ulrich M. Gassner, Thomas Wagner, Martin Kammel
Abstract
• The terms “point-of-care testing (POCT)” and “near-patient testing (NPT)” and their implications in EU, US and Australian legislation are discussed. • A classification scheme for laboratory test systems according to their technical complexity and required operator competence is provided and applied for SARS-CoV-2 associated analyses. • A simple method for evaluating the independence of operator activities of NPT/POCT assays is presented. European legislation defines as "near-patient testing" (NPT) what is popularly and in other legislations specified as "point-of-care testing” (POCT). Systems intended for NPT/POCT use must be characterized by independence from operator activities during the analytic procedure. However, tools for evaluating this are lacking. We hypothesized that the variability of measurement results obtained from identical samples with a larger number of identical devices by different operators, expressed as the method-specific reproducibility of measurement results reported in External Quality Assessment (EQA) schemes, is an indicator for this characteristic. Legal frameworks in the EU, the USA and Australia were evaluated about their requirements for NPT/POCT. EQA reproducibility of seven SARS-CoV-2-NAAT systems, all but one designated as "POCT", was calculated from variabilities in Ct values obtained from the respective device types in three different EQA schemes for virus genome detection. A matrix for characterizing test systems based on their technical complexity and the required operator competence was derived from requirements of the European In Vitro Diagnostic Regulation (IVDR) 2017/746. Good EQA reproducibility of the measurement results of the test systems investigated implies that different users in different locations have no recognizable influence on their measurement results. The fundamental suitability of test systems for NPT/POCT use according to IVDR can be easily verified using the evaluation matrix presented. EQA reproducibility is a specific characteristic indicating independence from operator activities of NPT/POCT assays. EQA reproducibility of other systems than those investigated here remains to be determined.