The quality of bacterial infection serology tests in Germany: Evaluation of the 2020 external quality assurance schemes – a report by the Quality Assurance Commission of the German Society for Hygiene and Microbiology

External quality assurance (EQA) tests are used to validate diagnostic testing procedures in the context of quality assurance. They are mandatory and the frequency of participation varies depending on the parameters and whether the test is offered by the laboratory. Samples are analyzed under routine conditions by each EQA test participant and the measurement results are transmitted to the reference institute (Richtlinie der Bundesärztekammer zur Qualitätssicherung laboratoriumsmedizinischer Untersuchungen [guideline of the German Medical Association for the quality assurance of laboratory medical examinations] 2023). The results of the 2020 EQA schemes are presented in more detail below.