The quest for comparability: Calibration 2000

 Most efforts in quality control have been focussed on the reduction of intralaboratory variation and the assessment of interlaboratory variation. Over the last few years, the importance of bias in interlaboratory variation and intralaboratory shifts has become clear. Small shifts can sometimes have a large impact on the number of treated patients, particularly in assays where cut off values are used. For example in cholesterol, HDL-cholesterol, HbA1c and TSH assays. There is an obvious need for adequate calibration material. However, the process of development of international primary reference materials and reference methods takes time, and even if reference materials exist and are used by in vitro diagnostics manufacturers, there still remains significant and clinically relevant interlaboratory variance and intralaboratory shifts, as is seen, e.g. in protein chemistry. The harmonization of inter laboratory and intralaboratory results needs an impulse from professional organizations to convince individual laboratories of the importance and significance of bias. This applies to all subdisciplines of laboratory medicine. On the occasion of the 25th anniversary of the Foundation for External Quality Assessment (SKZL), a large interdisciplinary harmonization project called Calibration 2000 was launched in The Netherlands The strategy and first results are reported in this paper. The project aims at harmonization of laboratory data of several disciplines, using secondary calibration materials, leading to common reference ranges throughout The Netherlands. Received: 15 April 2000 · Accepted: 15 April 2000