Normalized MEDx chart coupled with Quality Goal Index for evaluation of analytical quality achievements and quality shortcomings. A novel perspective to its further application

Evaluation of the analytical performance of endocrine analytes using sigma metrics

“…Though the normalized QC performance decision chart provided visual performance differences of the analytes, it could not present the reasons for quality errors such as those caused by imprecision, inaccuracy, or both. This phenomenon was also observed by Qiu HW et al 22 The QGI analysis was to remedy this defect by providing easy insights into where sigma quality improvement was required. Further to this, the RCA analysis provided a structural and standardized framework to investigate five potential causal factors (Table ).…”

“…The normalized QC performance decision chart was constructed by registering an account in the CLInet (http://www.clinet.com.cn) with CV/TEa as abscissa and Bias/TEa as ordinate 16‐18,20,21 . The chart is divided into six grades by five lines 22 . Based on the sigma level, the performance of the analytes was divided into six grades 23 : world‐class (σ > 6), excellent (5 ≤ σ < 6), good (4 ≤ σ < 5), marginal (3 ≤ σ < 4), poor (2 ≤ σ < 3), and unacceptable (σ < 2) (Figure 2).…”

“…[16][17][18]20,21 The chart is divided into six grades by five lines. 22 Based on the sigma level, the performance of the analytes was divided into six grades 23 : worldclass (σ > 6), excellent (5 ≤ σ < 6), good (4 ≤ σ < 5), marginal (3 ≤ σ < 4), poor (2 ≤ σ < 3), and unacceptable (σ < 2) ( Figure 2). The sigma value of the analyte was represented by colored circles marked in certain sigma grades of the chart when the parameters of the analyte's name, TEa, bias, and CV were inputted into the interface.…”

Application of biological variation and six sigma models to evaluate analytical quality of six HbA 1c analyzers and design quality control strategy

“…QGI < 0.8 indicated that the main reason for the poor performance of the method was that the low precision; QGI > 1.2 indicated that the accuracy of the method is poor and should be improved. If QGI was between 0.8 and 1.2, both the precision and accuracy needed to be improved [9].…”