Quality Assurance

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Reference Laboratories of IRAN Hematology
Lab. Dr. Atoosa Shariat Torbaghani
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Quality Assurance Programme

• Internal Quality Control (IQC) Procedures
• External Quality Assessment (EQA)
• Quality Management

The ultimate goal of quality system is to obtain
test results that are Reliable, relevant and
reproducible.
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Internal Quality Control

• Done during daily routine work
• Provides an immediate control
• Errors are corrected immediately

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External Quality Assessment

• Evaluates past performance
• Testing of unknown samples
• Compare performance with others
• Provides a forum for improvements and correction
  of errors

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Quality Management

• Training of laboratory staff
• The use of SOPs
• Standard supply management
• Standard equipment management
• Supervision and organization

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Why do we need Internal Quality Control?

• Ensure that test results are reliable
• Ensure that test results are reproducible
• Control quality of daily routine work

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Why do we need External Quality Assessment?

• To detect hidden problem
• To receive help and support from the NPHL
• To compare our performance with others and
  improve quality

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Why do we need Quality Management?

• Enable us to produce quality results
• Ensure that test results are affordable
• Ensure that test results are relevant
• Ensure that test results are interpreted correctly

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• Quality Control
• Operational techniques and activities that are
  used to fulfill requirements quality for quality
• Quantitative and statistical
• AIM to reduce both systematic and random error
• Quality Assurance
• All those planed and systematic actions necessary
  to provide adequate confidence that a product,
  process or service will satisfy requirements for
  quality

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Quality assurance programmes

• Non-analytical QC
• control of procedures not directly associated
  with the measuring of a parameter

• Analytical QC
• control of procedures
• directly associated with the measurement of a
  parameter

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Quality Assurance Targets

• Preanalytical Process
• Patient preparation,
• Specimen collection, Anticoagulant, labeling,
  storage, transportation
• Postanalytical Process
• How report, speed of report,
• never rely on a single value (out of reference
  range) to make a diagnosis
• oslers rule Try to attribute all abnormal
  findings to a single case
• Analytical Process
• Internal QC
• External QC

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Statistical procedure

• Meansum of all measurement divided by the number
  of measurement
• Medianpoint on the scale at which there is an
  equal number of observation that are above and
  below
• Mode the most frequently occurring result in
  the set
• SD
• CV

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mean
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median
???
???
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Accuracy vs Precision
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Normal Distribution CurveGaussian Curve

• 1SD68 2SD97 3SD99
  

1SD 2SD 3SD
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Formulae

• ?(x - x )
• Variance S2 n - 1
• Standard deviation ?S2
• SD x
  100
• Coefficient of Variation x

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Quality assurance programme

• a)At all time
• Correlation system
• -Blood film with blood count
• -Blood count with clinical data

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Correlation system

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.QA prog.

• b) Daily
• Test on control specimen
• Levey jenning control chart
• 2. Duplicate test on patents specimen
• 3. Check test
• 4. Delta test
• 5. Daily mean

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Quality Chart Control

• mean2sd
• mean
• mean-2sd
• days

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Control Chart example
2sd0.66
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Example
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Westgard Rules

• 1 2s warning
• 1 3s Reject
• 2 2s
• 4 1s
• R 4s
• 6 or 10 warning

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values drift, problem progressively developing
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shift abrupt change, values oscillate around new
mean
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• 1 2s RE
• 1 3s RE
• 2 2s SE shift
• 4 1s SE
• R 4s RE shift
• 6 or 10 X SE

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Error

• Random error variance
• Increase scatter of value about the true value
• Results of chance(eg.sampling error)
• Dont affect an entire batch of specimens
• Are not be detected by control samples
• Systematic error bias
• not due to chance
• eg.deteriorating reagents

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Random Error

• Incomplete mixing
• Bubble or particle in reagent
• Probe and syringe variation
• Optical problem
• Sample line problem
• .

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Systematic Error

• Inaccurate standard
• Poor calibration
• Inadequate blank
• Improperly prepared reagents
• Degradation of reagent
• Drift of detector
• Degradation of instrument components
• Improper setting of temperature bath
• ..

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Duplicate Test
2sd1.5
dgt2sd?random error
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Check Test

• Similar to Duplicate Test
• But for samples of same day
• Detection deterioration of apparatus and reagent
  between tests
• Suitable for Hg Rbc ( 4-5 samples)

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Delta Test

• Hg gt 10
• RBC gt 10
• WBC gt 20-25
• Plat gt 50

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Daily Mean (Bulls Method))

• Assume the population sampled each day remains
  constant
• Automation MCV,MCH,MCHC
• Manual MCHC
• If has minimum 100 sample/day
• Mean each Bach (n20) gt 2sd ? systemic error

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Example
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..QA prog.

• D) Monthly
• Reagent Kits check (storage, expire date)
• Sample collection,
• anticuagulant,storage
• Precision of cell counter
• Blood film
• ( distribution, staining)

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.QA prog.

• E) Every six month
• (Photometer spectrophotometer,) calibration
• (Sampler pipette) calibration
• Other instruments

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External Quality Assessment

• Consensus method
• Sd , 2sd , mean
• Deletion results gt mean 2sd
• Again sd , 2sd , mean

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Deviation index

• lt0.5 excellent
• lt1 satisfactory
• 1-2 satisfactory but borderline careful
  watch)
• 2-3 requires review of techniques check on
  calibration
• gt3 require urgent investigation

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Standard Operating Procedure

• SOP is an important part of QA
• It is instruction protocol that include all
  aspects of laboratory practice
• SOP helps prevent mistakes rather than detecting
  them

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SOP have the following features

• Accordance with a standard format
• In simple language, readily understood by
  employees
• Contain sufficient details to perform
• Sop are written by qualified experienced lab
  officer
• It must be followed exactly by all staff
• It must be given a title, identification number
  and date
• Sop reviewed and update on a regular basis

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SOP include

• Title id number date
• Staff able to perform test
• Principle of the test method
• Clinical significance of the test
• Specimen
• Equipment requirements
• Reagent Stain requirement
• Test procedure instruction( step by step)
• Calculation Expected value
• Reporting and interpretation of results
• Internal quality control procedures and Sources
  of error
• Reference

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Blood film must be examine in

• First time blood count with any abnormal
  parameters
• Hematology out-patients at every visit
• Weekly on Oncology clinic patients
• Weekly on patients undergoing radiotherapy or
  cytotoxic drug treatment
• All neonatal and pediatric patient

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..

• Patients with lymphadenopathy ,
  hepatosplenomegaly , or with glandular fever or
  flu-like symptoms
• Patients with fever in or coming from malaria
  area ( unless diagnosis of malaria has already
  been confirmed)
• When the blood count by an automated analyzer has
  been flagged e.g. because of microcytosis,
  agglutination, cell fragments, platelet clumps.

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Data specimen Retention

• Request forms 3 months
• Copies of records 3 m
• Result work-book 5 year
• Blood group 10 year
• EDTA blood specimen 7 days (hg) at
  4ºC
• Citrated blood sample 3 weeks at
  4ºC
• Blood films 5
  years

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EDTA

• Mechanism
• Increase / decrease effect
• Storage transport
• Kinds of
• EDTA-Na2,2H2o ? 1.4-2 mg/ml solid
• EDTA-K2,2H2o ? 1.5-2.2 mg/ml
• EDTA-K3 ? 1.5-2.2 mg/ml liquid

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Calculation

• Concentration 1.5 mg/1cc blood 3 mg / 2 cc
• EDTA solution 3 ? 3gr/100cc or 30gr/1000cc or
• 30000mg/1000cc
• 1000cc 30000mg X3000/300000.1
• X 3mg ? 100 ?l for 2cc
  blood
• EDTA solution 1 1gr/100cc or
  10g/1000cc or
• 10000mg/1000cc
• 1000 10000mg X3000/100000.3cc
• X 3mg ? 300 ?l

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EDTA

• NEVER add the blood before EDTA solution
  completely dried
• Dilution blood and destroy RBC

• NEVER add EDTA powder directly to the sample
  bottle
• Shrinkage of RBC
• Destroy WBC plt