Thyroid-stimulating hormone and free thyroxine on the ADVIA Centaur immunoassay system: a multicenter assessment of analytical performance.

OBJECTIVES We assessed the analytical performance of the TSH and FT4 assays on ADVIA Centaur in a multicenter national evaluation. DESIGN AND METHODS A precision study and a method comparison were performed. Reference values stated by the manufacturer were checked from 379 normal subjects. RESULTS For TSH and FT4, the intra-assay CVs were below 2.3 and 5.2%, respectively, and the inter-assay CVs below 4.4% and 7.2%, respectively. Therefore, the precision and reproducibility were acceptable. Bland-Altman bias plots revealed good correlation and agreement with Cobas assays. TSH and FT4 data yielded reference ranges of 0.64-3.24 mIU/L and 10.5-18.9 pmol/L, respectively. CONCLUSION These assays demonstrate reliable characteristics. The reference ranges obtained can be used for interpretation of thyroid function.