Introduction to Quality Control

Authors: Jean Houger Hengesbaugh, MS, CLS(NCA) and Brad Westover, BS
Reviewer: Joshua J. Cannon, MS, MLS(ASCP)CMSHCM
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Continuing Education Credits

P.A.C.E.® Contact Hours: 1 hour(s)

Florida Board of Clinical Laboratory Science CE Credit Hours

Florida Board of Clinical Laboratory Science CE - Supervision/Administration, Quality Control/Quality Assurance, and Safety: 1 hour(s)

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This course presents the basics of quality control in the clinical laboratory. Topics include assayed and unassayed controls, Levey-Jennings plots, Westgard rules, and standard deviation.

Objectives

  • Explain the purpose of a quality control program.
  • Define assayed and unassayed controls and the advantages/disadvantages of each type.
  • Discuss various quality control tools.
  • Prepare a Levey-Jennings control chart.
  • Explain the Westgard QC multi-rule approach.
  • Define random and systematic errors and causes for each.
  • Define accuracy and precision and discuss the statistical tools that are used to monitor each.

Course Outline

  • Introduction to Quality Control
    • Quality Control and a Quality Control Plan
    • Which of the following may be included in a quality control plan?
  • Quality Control Tools
    • Quality Control Tools
    • Intralaboratory (Internal) Quality Control
    • Assayed and Unassayed Controls
    • Internal Quality Control Program
    • Determining the Frequency for QC Testing
    • Additional Variables
    • Instrument Maintenance
    • Record Keeping
    • External Quality Assessment
    • Commercially available control materials for some laboratory instruments or method systems may be assayed or unassayed. Both will monitor the method system's accuracy and precision. However, there are differences between them. Match each of the following characteristics to either assayed or unassayed controls.
    • True or False: If a laboratory is part of a system, it can compare its proficiency testing (PT) results with other laboratories in the system prior to submitting the results to the PT provider.
    • Delta Checks
  • Statistical Analysis of Control Data
    • Accuracy and Precision
    • Mean and Standard Deviation
    • Calculating Acceptable Ranges
    • Calculating Acceptable Ranges, continued
    • Coefficient of Variation
    • Choose, for each statement, to what it refers to: the mean, standard deviation, or coefficient of variation.
    • For a particular method, a control has a mean result of 12 with a standard deviation (SD) of 2. What is the acceptable 95% range for this control?
  • Quality Control Charts
    • Levey-Jennings Quality Control Charts
    • Random and Systematic Errors
    • Random and Systematic Errors, continued
    • Westgard Multi-Rule Approach
    • Westgard Multi-Rule Approach, continued
    • Responding to Out-of-Control Results
    • Which type of error does each rule usually detect?
    • A laboratory uses these Westgard QC rules as criteria for rejecting an analytical run: 13s, 22s, and R4sThe top chart is for control #1 and the bottom chart is for control #2. On which days are there QC violations?
  • References
    • References

Additional Information

Level of Instruction: Basic
Intended Audience: Medical laboratory scientists, medical laboratory technicians, laboratory supervisors, and laboratory managers. This course is also appropriate for MLS and MLT students and pathology residents. 
Author Information: Brad Westover, BS received his BS in Physics in 2006 from the California Institute of Technology. He is pursuing a Ph.D. at the University of California, San Diego.
The author has no conflict of interest to disclose.
Reviewer Information: Joshua J. Cannon, MS, MLS(ASCP)CMSHCM received his Bachelor of Science and Master of Science in Medical Laboratory Science from Thomas Jefferson University in Philadelphia, PA. He holds Medical Laboratory Scientist and Specialist in Hematology certifications through the ASCP Board of Certification. He was a professor at Thomas Jefferson University for seven years before transitioning into his current role as Education Developer at MediaLab by Vastian. His areas of expertise and professional passions include clinical hematology and interprofessional education.
Course Description: This course provides important fundamental concepts in quality control that are useful to laboratory personnel who report patient results. Topics include precision, accuracy, random and systematic errors, standard deviation, mean, coefficient of variation, quality control tools, and an overview of the Westgard multi-rule approach for evaluating QC results