5Nevalainen D,Berte L,Kraft C,et al.Evaluating laboratory performance on quality indicators with the six sigma scale[J].Arch Pathol Lab Med,2000,124(4),516-519.
6Westgard JO.Six Sigma Quality Design and Control[M].2nd ed.Madison:Westgard QC2006:157-184.
7Westgard JO,Westgard SA.The quality of laboratory testing today:an assessment of σ metrics for analytic quality using performance data from proficiency testing surveys and the CLIA criteria for accep table performance[J].Am J Clin Pathol,2006,125(3):343-354.