To evaluate the analytical performance of endocrine testing using six sigma(σ), and find the cause of dissatisfied performance for some projects combined with the quality goal index (QGI), so that provide rectification direction for the improvement of the endocrine projects quality.

Nine endocrine items which participated in the clinical laboratory external quality assessment (EQA) of the Ministry of Health in 2016 was selected in this study. The two levels of laboratory internal quality control were accumulated in coefficient fo varivation (CV), respectively, as the estimation value. By adopting the quality evaluation standard of the Ministy of public healty the acceptable range of endocrine items was measured as the total allowah error (TEa). CV and Bias with the data of internal quality control (IQC) and EQA was evaluated. The sigma metrics based on the TEa from the National Center for Clinical Laboratory were in accord with the formula σ=(TEa-|Bias|)/CV for each endocrine test. Quality goal index(QGI) was also calculated to investigate the reason for dissatisfied performance as follows: QGI=Bias/(1.5*CV). Evaluate the quality levels of nine endocrine tests with σstatistics. Analyze which improvement measures were needed for each project with QGI.

In low level of IQC, the rates of endocrine items for 4≤σ<5σ, 3≤σ<4, σ<3 were 22.22%, 44.44%, 33.33%, respectively. In high level IQC, the rates of endocrine items for σ≥6, 5≤σ<6, 4≤σ<5, 3≤σ<4, σ<3 were 11.11%, 11.11%, 11.11%, 55.56% and 11.11%, respectively. In the dissatisfied performance of the endocrine tests, which the QGI<0.8 include FT3, FT4, FSH, LH, Prog, Folate, VitB₁₂, which the QGI>1.2 include TSH, T.

Sigma performance verification can be used to evaluate the performance of laboratory testing projects. The sigma and QGI can be used for investigation of the reason for dissatisfied perfarmance of the project, and guiding the improvement of clinical laboratory quality.