TY - JOUR A1 - Wojtalewicz, Nathalie A1 - Schellenberg, Ingo A1 - Hunfeld, Klaus-Peter T1 - Evaluation of INSTAND e.V.’s external quality assessment for C-reactive protein and procalcitonin T2 - PLoS one N2 - Background: The purpose of this paper was to analyze the general diagnostic strength and performance of in vitro diagnostics for C-reactive protein and procalcitonin based on the results of external quality assessment schemes (EQAs). Methods: We analyzed qualitative and quantitative data on both markers collected by the Society for Promotion Quality Assurance in Medical Laboratories (INSTAND e.V.) from 20 EQAs. The C-reactive protein evaluation was method-specific and the procalcitonin evaluation manufacturer-specific (pseudonymized). Coefficients of variation were determined in order to evaluate interlaboratory comparability and the performance of individual laboratories during the analyzed period was examined. Results: Overall most of our participants were able to correctly distinguish the positive from the negative samples, but we occasionally observed also false-positive results for the immunological detection of C-reactive protein. For the semi-quantitative results of C-reactive protein we observed an overall median difference below 5% except for dry chemistry methods (≤ 21%). For procalcitonin two manufacturer collectives showed a good comparability, while one manufacturer detected up to 42% higher results. The coefficients of variation are promising for both analytes even though they surpass the manufacturer’s indication for some collectives. The performance of individual laboratories during the analyzed period was more stable for C-reactive protein than for procalcitonin. Conclusion: In-vitro diagnostic testing for C-reactive protein and procalcitonin showed promising results in our EQAs but still further improvements are needed. We recommend stepping up research on reference measurement methods for both parameters to possibly enhancing the accuracy and diagnostic strength of such assays. KW - C-reactive proteins KW - Diagnostic medicine KW - Inflammatory diseases KW - Biomarkers KW - Independent laboratories KW - Infectious diseases KW - Pediatric infections KW - Sepsis Y1 - 2019 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/50748 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-507482 SN - 1932-6203 N1 - Copyright: © 2019 Wojtalewicz 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. VL - 14 IS - (8): e0221426 SP - 1 EP - 14 PB - PLoS CY - Lawrence, Kan. ER -