good laboratory practices with waived test systems

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Good laboratory practices with waived test systems. 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 - PowerPoint PPT Presentation


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

  • What is a waived test?Under CLIA, tests are categorized by complexityWaived, PPMP, Moderate, HighWaived tests are:Simple lab examinations or proceduresCleared by FDA for home useNegligible likelihood of erroneous resultsNo reasonable risk of harm if performed incorrectly

  • What does waived mean?Waived from most requirements established for tests of higher complexitySite inspections are not routinely performedProficiency testing is not requiredPersonnel qualifications are not established

  • What do the Washington State regulations say for waived testing?

    Obtain a Medical Test Site licenseTell us which waived tests you performFollow manufacturers instructions for performance of the test

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

  • Have a current product insertMake sure it states CLIA waivedFor 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 sectionsIntended useProduct storagePrecautions/WarningsPatient preparationSpecimen collection Test procedureProcedural notesQuality controlResults/InterpretationLimitations 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 useDescribes what is actually being measuredmeasures percent concentration of HgbA1C in bloodQualitative versus quantitative qualitative detection of Group A Strep antigen directly from throat swabType of specimennot recommended for use with gastric specimens

  • Product storageKits, reagents, test devicesstore refrigerated at 2 8 degrees C keep 3 months at room temperaturecassettes must be stored in sealed foil pouchesstore out of sunlightstrips must be kept in bottle with cap tightly closed

  • Precautions / WarningsProper handling of kits, reagents, test devicesdo not use past expirationdo not mix components of different lots or kitsshould not be interpreted by individuals with blue color deficiency (color blindness)do not interchange caps on reagents

  • Patient preparationExamples:CLO testdiscontinue use of antibiotics and bismuth preparations 3 weeks before biopsyOccult bloodfor 7 days avoid non-steroidal anti-inflammatory drugs, for 3 days avoid vitamin C in excess of 250 mg a day, avoid red meats

  • Specimen collection, handlingAcceptable types of specimensfinger stick or venipuncturecan be stored at room temperature for 4 hours and up to 72 hours if refrigerateddo not use swabs that have cotton tips or wooden shaftsAcceptable anticoagulantsacceptable anticoagulants are EDTA, heparin, citrate, fluoride

  • Test procedure/Directions/InstructionsFollow exactly Dont modifyAdhere to timing

  • Procedural notesdo not open foil pouch until ready to test avoid cross contamination read results within 20 minutesdirections must be followed exactly, accurate timing is essentialallow specimen and test devices to warm to room temperature before use

  • Quality controlThe types of controls to be tested vary with the specific test system usedExternal, Internal, ElectronicTest controls according to the manufacturers instructionsRead the entire Quality Control section carefullyAssure that you get the expected results for the controls tested

  • Quality controlExternal controlsReference solutions or materials (i.e., swabs)Added to test device like the patient sampleMay be included with the test kit or you may need to purchase separatelyCompare your control results to the expected ranges or values printed on the control vials or in the control product insert

  • Quality controlInternal (built-in, procedural) controlsBuilt into test reagent devices to ensure that reagents are active, reagents & samples are added correctly, test performs according to specificationsCommon with qualitative tests (Strep antigen, pregnancy, H. pylori, mononucleosis)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 controlElectronic controlsInert, reusable devices (test strips, cartridges, cassettes) Used to check instrument performance specificationsAvailable for use with some quantitative test systems (hemoglobin, cholesterol, A1C, prothrombin time)Compare the control results with the expected values

  • Results / Interpretation PositiveNegative InvalidReportable range of methodpatient values are linear from 2.5% to 14.0%linear up to 23.5 g/dl

  • Limitations of procedureCauses of false positives, false negativespatients must have a total hemoglobin between 7 and 24 g/dlmeasuring range is 100 to 500

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

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

  • Good laboratory practicesAt minimum, test external controls with each new lot of kits, reagents, testing devicesTo detect problems during shipmentObserve internal (built-in, procedural) controls with each patient testTo assure proper test performance, reagent integrityTest electronic controls periodicallyAccording to manufacturers instructions & frequency

  • Good laboratory practicesCorrelate test results with patient presentation, history, diagnosis Participate in a proficiency testing (PT) programMany PT companies offer 2 sample programsSplit sample programCompare your results with reference laboratory

  • TrainingHave new employees read the entire product insertNot just the Quick Reference CardKeep a record of trainingHave each employee demonstrate competencyInitiallyPeriodically

  • Keep a simple log of resultsBy keeping results of the following in chronological order, you can detect potential problems:New lots of reagents, kits, testing devicesQuality control resultsPatient test results

  • Report test system problemsTo manufacturerTo Food & Drug Administrations MedWatchCall 1-800-FDA-1088

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


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