This lesson discusses one of the cornerstones of QC practice. We can no longer take for granted that everyone knows how to build a control chart, plot the control values, and interpret those results correctly. Patricia L. Barry, co-author of Cost-Effective Quality Control: Managing the Quality and Productivity of Analytical Processes, provides a primer on how to construct, use, and interpret the Levey-Jennings chart.
This lesson discusses the math involved with QC practice. Despite the age of computers, we still have to crunch the numbers ourselves sometimes. Dr. Westgard discusses the terms Mean, SD, CV, Control Limits, z-scores and SDI's, explaining what they are, giving the equations, and demonstrating how to calculate them.
Elsa F. Quam, BS, MT(ASCP) is one of our most popular guest essayists. Elsa rightly points out that while we concentrate on the statistics of quality control, we can't forget the selection of the control materials. Important attributes such as the stability, vial to vial variability, assayed versus unassayed, appropriate analyte levels, and pretreatment procedures affect the very success of the control procedure.
An introduction to the theory and concepts of quality control in the healthcare laboratory. Dr. Westgard also gives a preview of the articles that follow in this critical series on Basic QC Practices.
