Proficiency tests to evaluate commercially available IVD kits for glucose and cholesterol measurements

The first proficiency testing round 630-IL-1002, was carried out with a Reference Material DMR-180a with reference values obtained by using gas chromatography isotope dilution mass spectrometry methods, in which glucose, cholesterol and creatinine were measured. The serum pool was obtained from blood donors and all the analytes were at the normal concentration in Mexican population. The laboratories participants used different field methods to measure the analytes. The Mexican compulsory standard NOM-064-SSA1-1993 “specifications for equipments in vitro diagnostic (IVD)” requests 5% precision and 5% maximum bias of the IVD equipments in the measurements of analytes like glucose and cholesterol. The results obtained by field laboratories in the proficiency testing round are compared to the reference value and uncertainty provided by the National Metrology Institute (CENAM). The quality of measurements is dependent not only on the laboratory competence but also on the methods used by those commercially available IVD kits. It is concluded that quality assessment of measurements in clinical laboratories should be critically evaluated by using stable and certified reference materials.