QC Design
A simple example planning QC for potassium using power function and critical-error graphs.
An example planning QC for cholesterol using an analytical quality requiremen - from CLIA proficiency testing criteria for acceptability.
Immunoassay methods often have higher CVs than observed for routine chemistry and hematology tests. Laboratory QC practices often involve analyzing 3 or 4 different levels of controls and sometimes analyzing these controls in duplicate. In planning QC for such applications, it is useful to assess the error detection and false rejections characteristics of higher N multirule QC procedures and see how they compare with the performance from more common QC procedures having Ns of 2 to 4.
How do you select QC for 18 different tests on a multitest instrument? Dr. Westgard illustrates how it's done, using the critical-errors graphs, and also explains how it can save money.
This cholesterol example illustrates the use of a clinical quality requirement based on the National Cholesterol Education Program's guidelines for use and interpretation of a screening cholesterol test. OPSpecs charts designed for clinical quality requirements are used to plan QC for cholesterol based on these guidelines.