Reference values and methods comparison of a new testosterone assay on theAxSYM system

Objectives: We have contributed to the Design Validation Protocol of the ne w Abbott AxSYM Testosterone assay with a study on reference values and meth ods comparison. Design and methods: For reference values a population of 45 women and 30 me n was tested. In methods comparison, 132 samples for the AxSYM vs. ACS-180, and 30 for the AxSYM vs. Elecsys were used. Pearson and intraclass concord ance coefficients and Passing-Bablock test were performed for overall group , men and women. Results: Reference values were 0.9-3.1 (females) and 1.0-30.2 nmol/L (males ). Globally, a good agreement between methods in both the AxSYM vs. ACS-180 (slope: 0.88, gamma-intercept: 0.67, r = 0.961) and the AxSYM vs. Elecsys (slope: 1.08, gamma-intercept: 0.31,r = 0.935) studies was found. Slightly worse results were observed for women. Conclusions: The reference range of testosterone by the AxSYM system matche s with those published for other methods. An acceptable agreement between t he AxSYM Testosterone assay and both a classical (ACS-180) and a more recen t (Elecsys) methodology was observed. Copyright (C) 2000 The Canadian Socie ty of Clinical Chemists.