Basics of laboratory quality assurance.

1. Quality Assurance
Gift Ajay Sam
Sr. Demonstrator/ Dy. Quality Manager
Department of Transfusion Medicine and
Immunohaematology
CMC, Vellore
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2. Overview
• Introduction to quality
– Definition of Quality
– Definition of Quality Management
– Core value of QM
• Quality assurance vs Quality control
– Quality control
– Proficiency testing
– Calibration
• Documentation
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3. Quality?
• Conformance to requirements_ Philip Crosby.
• Exceeding what customers expect form
service_ Paraguan and Berry.
• User based, product based, manufacturing
based, value based and transcendent view_
Gravin.
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4. Quality
“Quality is the degree to which a set
of inherent characteristics fulfils
requirement”_ ISO 9000
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5. Quality Management
• Quality: Fulfilling requirements.
• Management:
– Plan
– Organize
– Staff
– Lead/ direct
– Control
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6. Quality + Management
Plan, organize, staff, lead and control
to fulfilling the requirements of the
customer (patient/ lab service user).
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7. Core values of Quality Management
• Customer (lab service users) focus
• Initiation from top management
• Involvement of all staff
• Process approach (profit maximization by waste
minimization)
• System approach to management (Management
of interrelated processes)
• Kaizen (Continual improvement)
• Factual approach for decision making
• Mutually beneficial supplier relationship
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8. Quality assurance vs Quality control
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9. 3 major differences
Quality Assurance Quality Control
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Management system to
guarantee integrity of data.
Measurement used to check
quality of analytical data.
2 Everybody’s business
Restricted to a specific area
and performed by authorized
staff.
3 Goal is value addition Goal is error prevention
4 Management strategy Error detection methodology
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10. QUALITY CONTROL
Selection
Frequency
Evaluation
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11. Quality Control- Selection
• Cover the analytical measurement range e.g.
low, normal and high.
• Product stability over a long period of time
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12. Frequency of QC runs
• Stability of method (QC at least once in 24 hr or
more if manufacturer or lab determines so. (CLSI
regulation, section 493.1256)
• Risk of harm to patient
– Clinical action that can be taken before error could be
detected.
– Frequent QC can identify methodological problems
earlier.
• Number of results to be repeated in case of
failure.
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13. QC at Immunohaematology
• In should cover a range of analytical
parameters i.e. grouping, rH typing, DAT, IAT.
• In case of HGB quantification it should check
performance at low, normal and high.
• In case of screening for TTI the controls should
be positive/ negative.
• Other parameters to consider are cost and
availability.
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14. Evaluating QC results
• Control charts
– Extreme- 1 value exceed 3SD
– Bias- > 9 values on one side of chart.
– Trend- > 6 continually points increase or decrease
– Oscillation- Opposite directions over and over again.
– On edge- 2 or 3 points exceed 2SD in same direction
– Tendency- 9 (of 10) points on one side of the mean
– Blissful ignorance- > 8 points in a row within 1SD,
distributed on both sides of the mean.
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15. Other features of QC runs
• QC run variability is usually expressed in terms
of SD.
• N= 20 as per CLSI 2006 guidelines.
• It is recommended that the SD should be
established from a single lot of QC reagents
considering the values over a period of 6 – 12
months. This will represent the variability
better.
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16. Patient samples in QC
• Consistency of results with reagent lot change
and post calibration.
• Delta check with previous results
• Verification of consistency of results b/w
instruments.
• Checking method performance as part of
instrument validation
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17. Proficiency testing/ EQA
• Evaluating method performance by
comparison of results with other laboratories
on the same set of samples.
• Goal of PT/ EQA
– Result harmonization among peers
– Method accuracy (Need for calibration or any
other form of correction to ensure accurate
results).
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18. Calibration
• Performed using a calibrator.
• Calibrator results are traceable to the highest
order of reference system.
• Calibrators for instruments are usually
provided by the manufacturer themselves.
• CLIA regulation 493.1255 recommends
methods have to be calibrated at least every 6
months or more frequently if recommended
by the manufacturer.
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19. Calibration verification
• When no change in method performance has
occurred it is acceptable to verify that
calibration has not changed.
• Verification is commonly done by using
calibrator as a “unknown material”.
• The laboratory should establish the calibrator
target value for calibration verification, like
+1 SD from target value can be considered.
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20. DOCUMENTATION
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21. Documentation
Indicators for good documentation:
• Approved, reviewed and updated regularly.
• Concise, legible, accurate and traceable.
• Amendments & revision are identifiable.
• Current version is available at points of use.
• Follows change control procedure.
• Obsolete documents separated, identified and
retained for defined amount of time.
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22. Documents of the QMS
Quality
Manual
QSP/ SOP
Forms, checklist,
Records.
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23. Document classification in QMS
Internal documents External documents Records
Documents
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24. Document classification in QMS
• Internal documents:
– Documents/ reference material created by the
laboratory for use within the laboratory.
– It is subject to the change control procedures
created by the laboratory.
– It is approved by appropriate personal before
release for use by the laboratory personnel.
– E.g. SOP, QM, QSP.
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25. Document classification in QMS
• External documents:
– Maintained by the laboratory for reference
purposes.
– Created by a third party and is formally published
for use.
– Not subject to the change control procedure of
the laboratory.
– E.g. ISO 15189; 2012 standard, published book.
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26. Document classification in QMS
Records
• Proof/ evidence of activity.
• They have a defined retention period.
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27. References
• Henrys clinical diagnosis and management by
laboratory methods, 22 edition.
• The six sigma handbook revised and
expanded, Thomas Pyzedek.
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