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Good laboratory practices with waived test systems


Good laboratory practices with waived test systems January 2002 Washington State Department of Health ... (i.e., mononucleosis whole blood is waived, ... – PowerPoint PPT presentation

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Title: Good laboratory practices with waived test systems

Good laboratory practices with waived test
  • January 2002
  • Washington State Department of Health
  • Office of Laboratory Quality Assurance
  • (206) 418-5600

What is a waived test?
  • Under CLIA, tests are categorized by complexity
  • Waived, PPMP, Moderate, High
  • Waived tests are
  • Simple lab examinations or procedures
  • Cleared by FDA for home use
  • Negligible likelihood of erroneous results
  • No reasonable risk of harm if performed

What does waived mean?
  • Waived from most requirements established for
    tests of higher complexity
  • Site inspections are not routinely performed
  • Proficiency testing is not required
  • Personnel qualifications are not established

What do the Washington State regulations say for
waived testing?
  • Obtain a Medical Test Site license
  • Tell us which waived tests you perform
  • Follow manufacturers instructions for
    performance of the test

Waived tests are simple, but
  • Any test can produce erroneous results if not
    performed properly
  • Any test worth running should be associated with
    good laboratory practices
  • What are good laboratory practices?
  • What are good risk management practices?

Have a current product insert
  • Make sure it states CLIA waived
  • For some tests (defined in regulations) all are
    waived (i.e., fecal occult blood)
  • For some tests only certain specific test
    systems are waived (i.e., Strep antigen)
  • For some test kits test may be waived or
    moderate complexity, depending on specimen used
    (i.e., mononucleosis whole blood
    is waived, serum or plasma is moderate complexity

Focus on these sections
  • Intended use
  • Product storage
  • Precautions/Warnings
  • Patient preparation
  • Specimen collection
  • Test procedure
  • Procedural notes
  • Quality control
  • Results/Interpretation
  • Limitations
  • Expected results

  • In the following slides, we give examples (in
    quotations) from actual product inserts to show
    the kinds of information you will find in the
    various sections of the product insert

Intended use
  • Describes what is actually being measured
  • measures percent concentration of HgbA1C in
  • Qualitative versus quantitative
  • qualitative detection of Group A Strep antigen
    directly from throat swab
  • Type of specimen
  • not recommended for use with gastric specimens

Product storage
  • Kits, reagents, test devices
  • store refrigerated at 2 8 degrees C
  • keep 3 months at room temperature
  • cassettes must be stored in sealed foil pouches
  • store out of sunlight
  • strips must be kept in bottle with cap tightly

Precautions / Warnings
  • Proper handling of kits, reagents, test devices
  • do not use past expiration
  • do not mix components of different lots or kits
  • should not be interpreted by individuals with
    blue color deficiency (color blindness)
  • do not interchange caps on reagents

Patient preparation
  • Examples
  • CLO test
  • discontinue use of antibiotics and bismuth
    preparations 3 weeks before biopsy
  • Occult blood
  • for 7 days avoid non-steroidal
    anti-inflammatory drugs, for 3 days avoid
    vitamin C in excess of 250 mg a day, avoid red

Specimen collection, handling
  • Acceptable types of specimens
  • finger stick or venipuncture
  • can be stored at room temperature for 4 hours
    and up to 72 hours if refrigerated
  • do not use swabs that have cotton tips or wooden
  • Acceptable anticoagulants
  • acceptable anticoagulants are EDTA, heparin,
    citrate, fluoride

Test procedure/Directions/Instructions
  • Follow exactly
  • Dont modify
  • Adhere to timing

Procedural notes
  • do not open foil pouch until ready to test
    avoid cross contamination read results within
    20 minutes
  • directions must be followed exactly, accurate
    timing is essential
  • allow specimen and test devices to warm to room
    temperature before use

Quality control
  • The types of controls to be tested vary with the
    specific test system used
  • External, Internal, Electronic
  • Test controls according to the manufacturers
  • Read the entire Quality Control section carefully
  • Assure that you get the expected results for the
    controls tested

Quality control
  • External controls
  • Reference solutions or materials (i.e., swabs)
  • Added to test device like the patient sample
  • May be included with the test kit or you may need
    to purchase separately
  • Compare your control results to the expected
    ranges or values printed on the control vials or
    in the control product insert

Quality control
  • Internal (built-in, procedural) controls
  • Built into test reagent devices to ensure that
    reagents are active, reagents samples are added
    correctly, test performs according to
  • Common with qualitative tests
  • (Strep antigen, pregnancy, H. pylori,
  • Procedural controls typically include the
    appearance of a colored dot, line or bar in a
    control region and/or an expected appearance of
    the device background

Quality control
  • Electronic controls
  • Inert, reusable devices
  • (test strips, cartridges, cassettes)
  • Used to check instrument performance
  • Available for use with some quantitative test
  • (hemoglobin, cholesterol, A1C, prothrombin time)
  • Compare the control results with the expected

Results / Interpretation
  • Positive
  • Negative
  • Invalid
  • Reportable range of method
  • patient values are linear from 2.5 to 14.0
  • linear up to 23.5 g/dl

Limitations of procedure
  • Causes of false positives, false negatives
  • patients must have a total hemoglobin between 7
    and 24 g/dl
  • measuring range is 100 to 500

Expected results, values
  • the following values are considered normal
  • normal range is 4.3 - 5.7
  • 95 of prothrombin time values range from 10.6
    to 13.4 seconds
  • for the purposes of calculating the INR, normal
    is defined as 12.0 seconds
  • will detect 20 mIU/ml of HCG

Good laboratory practices
  • Test controls - Follow manufacturer instructions
  • positive and negative controls should be tested
    with each new lot or shipment of test materials
  • Daily Requirements Two levels of electronic
    quality control or two levels of liquid controls
    must be tested
  • a positive and negative control must be tested
    when opening a new test kit and with each change
    in operator within the test kit
  • check the calibration daily by using the control

Good laboratory practices
  • At minimum, test external controls with each new
    lot of kits, reagents, testing devices
  • To detect problems during shipment
  • Observe internal (built-in, procedural) controls
    with each patient test
  • To assure proper test performance, reagent
  • Test electronic controls periodically
  • According to manufacturers instructions

Good laboratory practices
  • Correlate test results with patient presentation,
    history, diagnosis
  • Participate in a proficiency testing (PT) program
  • Many PT companies offer 2 sample programs
  • Split sample program
  • Compare your results with reference laboratory

  • Have new employees read the entire product insert
  • Not just the Quick Reference Card
  • Keep a record of training
  • Have each employee demonstrate competency
  • Initially
  • Periodically

Keep a simple log of results
  • By keeping results of the following in
    chronological order, you can detect potential
  • New lots of reagents, kits, testing devices
  • Quality control results
  • Patient test results

Report test system problems
  • To manufacturer
  • To Food Drug Administrations MedWatch
  • Call 1-800-FDA-1088

  • Call the Office of Lab Quality Assurance
  • (206) 418-5600
  • Go to our website