Representation and performance of CE-marked and in-house <i>in vitro</i> diagnostic tests for routine laboratory parameters in external quality assessment programmes

IH-IVDs accounted for only a minimal proportion of tests. EQA results obtained with them showed no inferiority to those obtained with CE-IVDs. Furthermore, our findings show that EQA data are a useful tool for examining the analytical landscape, possibly even beyond the national level. Studies on the use and performance of IH-IVDs should be conducted based on EQA programmes for laboratory diagnostic areas where their proportion is likely to be higher.