Week 08: Quality Management in Labs

Week 08: Quality Management

• This week's topic is Quality Management in the clinical laboratory.
• Key objectives:
  • Describe quality control systems and validation methods in the lab.
  • Detail lab testing processes and potential errors.
  • Explain pre-analytical, analytical, and post-analytical variables and their effects on results.
  • Detail how to control pre-analytical, analytical, and post analytical variables.

Total Quality Management

• Total quality management (TQM) aims to improve the clinical lab.
• TQM focuses on controlling pre-analytical and analytical variables.
• External quality assessment and proficiency testing programs are essential components of TQM.
• Early problem detection prevents further issues.

Quality Management Cycle

• A cyclical process for quality management in the lab.
• Key components are: quality planning, quality improvement, quality laboratory process, quality assessment, and quality control.

Implementing Total Quality Management (TQM)

• PDCA (Plan-Do-Check-Act) cycle is fundamental to TQM implementation.
• Analytical processes, policies, practices, and work procedures are crucial for quality.
• Statistical and non-statistical control procedures (linearity checks, reagent and standard checks, and temperature monitoring) ensure quality.

Pre-analytical Variables Control

• Patient Identification: Correct patient and specimen identification is critical (at least 2 identifiers).
• Turn around time (TAT): Lab tests must be completed in an efficient manner. Accurate time recording, clear definitions for each test type and monitoring are vital. Specimen receipt in the lab, specimen collection, and test result reporting must be clearly defined.
• Laboratory Log (Specimen + Request): A log must be used for each specimen and request, with clear record-keeping, and accurate patient identification. Transcription errors can be a problem, especially with manual data entry.
• Patient Preparation: Patient factors that impact tests (recent intake of food, alcohol, or drugs, smoking, exercise, stress, sleep). Instructions and procedures should be clear.

Control of Pre-Analytical Variables (Continued)

• Specimen Collection: Proper handling procedures for specimens need to be in place, especially regarding preservatives and containers. Aliquot distribution is also important.
• Specimen Separation and Distribution: Use of centrifuges and appropriate containers.
• Specimen Transport: Transporting specimens appropriately (cooled, frozen, protected from light).

Non-controllable Variables

• Factors outside the lab’s control, including biological influences (age, sex, underlying medical conditions) and environmental factors (altitude, ambient temperature, geographic location, seasonal influence).

Week 09-10: Control of Analytical Variables

• Objectives:
  • Compare internal & external quality assessment programs
  • Understand the need for control material in clinical labs
  • Explain the use of control charts
  • Describe control limits calculation
  • Assess Levey-Jennings control charts and identify errors
  • Understand Westgard multirules for data interpretation

Control of Analytical Phase

• Employ validated analytical methods for lab testing.
• Calibration of analytical procedures is essential.
• Use quality control material specific to the assay.
• Monitor performance using Levey-Jennings charts.
• Apply Westgard multirules to interpret data.

Control of Analytical Variables (Continued)

• Ensure correct measurements through accurate methods.
• Key steps for reliable analytical procedures: selection, evaluation, implementation, maintenance, and control.

Control Material

• Control materials mimic patient sample characteristics.
• They should be stable and have clear composition.
• Control materials are used for a significant duration for precise control.
• Distinction between assayed (pre-determined target value) and unassayed (no pre-determined target value) control materials
• "In-house" pooled sera requires full validation.

Components of Quality Assurance

• Internal Quality Control (IQC): Lab professionals take steps to generate reliable results.

  • Focuses on the pre-analytical, analytical, and post-analytical phases.

• External Quality Assessment (EQA): A tool to assess IQC performance (inter-lab comparison).

Steps in Implementing Quantitative QC

• Obtain control material.
• Run each control 20 times over 30 days.
• Calculate the mean and +/- 1, 2, and 3 Standard Deviations (SD) from the data.

Measurement Procedure

• Determines quantity values.
• Includes measurement errors (difference between obtained and true value).
• Measurement errors have two components: random and systematic.

Random Errors

• Unpredictable analytical variations influence measurements.
• Possible causes: wrong pipetting techniques, inconsistent reactions timing/temperature, instability of instruments.

Systematic Errors

• Errors that affect measurements consistently.
• Possible causes: errors in calibrator values, degradation of calibration materials, incorrect reagent/sample volumes, improper reaction times/temperatures, incorrect instrument settings, calculation errors, and interference in samples.

QC Charts and Rules

• Levey-Jennings charts are critical for analyzing QC data.
• QC charts should include test name, date, source of control, and statistical data.
• Charts help identify analysis errors and prevent reporting of incorrect data.

Westgard Multirule Chart

• Use two control specimens in each analytical run (one normal, one abnormal) and plot them on the chart along with other data.
• Specific rules (12s, 13s, 22s, R4s, 41s, 10x) help in interpreting data and detecting and preventing errors.

Examining QC Charts

• Imprecision: Inconsistency in measurements, often due to operator error (e.g., pipette variability, lack of attention to detail).
• Inaccuracy: Errors in measurements, resulting in inaccurate data. Possible causes include reagents/standards degrading, instrument deterioration, introducing new procedures/new lots.
• Trends/Shifts: Changes in the results over time (e.g., a gradual increase or decrease in readings), which could point to issues needing investigation.

Control (Levey-Jennings) Chart Interpretation

• Continuous evaluation of control values.
• Interpretation of analysis results (acceptance or rejection based on different criteria).

This quiz covers essential concepts of Quality Management within the clinical laboratory setting. Topics include quality control systems, lab testing processes, TQM principles, and the quality management cycle. Understand the importance of managing pre-analytical, analytical, and post-analytical variables.