EXTERNAL QUALITY EXTERNAL QUALITY ASSESSMENT PROGRAM ASSESSMENT PROGRAM

(EQAP)(EQAP)BIOCHEMISTRY DEPARTMENTBIOCHEMISTRY DEPARTMENT

R. R. MohammadiMohammadiBiochemist (Ph.D.)Biochemist (Ph.D.)

Faculty member of Medical FacultyFaculty member of Medical Faculty

TWO COMPLEMENTARY TWO COMPLEMENTARY COMPONENETS OF TQM ARECOMPONENETS OF TQM ARE

••Internal Quality Control (IQC) Internal Quality Control (IQC)

••External Quality Assessment (EQA)External Quality Assessment (EQA)

INTERNAL QUALITY CONTROL INTERNAL QUALITY CONTROL (IQC)(IQC)

••Is necessary for the daily monitoring of Is necessary for the daily monitoring of precision and accuracy of analytical precision and accuracy of analytical

methodmethod

••Only Detects changes between present Only Detects changes between present performance and previous stable performance and previous stable

performance (Baseline)performance (Baseline)

••Undetected systematic errors during Undetected systematic errors during baseline period would included in the baseline period would included in the

mean that was used to calculate the mean that was used to calculate the control limits control limits

EXTERNAL QUALITY EXTERNAL QUALITY ASSESSMENT (EQA)ASSESSMENT (EQA)

••Is a process by which a laboratory uses an Is a process by which a laboratory uses an outside unbiased source to verify the quality of outside unbiased source to verify the quality of

patients results patients results

••allows a laboratory to confirm that its results are allows a laboratory to confirm that its results are consistent with those of other laboratories using consistent with those of other laboratories using

the same or similar methods for an the same or similar methods for an analyteanalyte and and thus to confirm it is using a method correctly thus to confirm it is using a method correctly

••Is important for maintaining the longIs important for maintaining the long--term term accuracy of the analytical methodsaccuracy of the analytical methods

EQAP HAS FOUR STAGESEQAP HAS FOUR STAGES

••Providing and Sending Quality Control (QC) Material to Providing and Sending Quality Control (QC) Material to Participating LaboratoryParticipating Laboratory

••Measuring Measuring Analyte(sAnalyte(s) and Reporting ) and Reporting Result(sResult(s) by ) by Participating LaboratoryParticipating Laboratory

••Data Analysis and Sending Evaluation Data Analysis and Sending Evaluation Report(sReport(s) to ) to Participating LaboratoryParticipating Laboratory

••Interpretation of Evaluation Interpretation of Evaluation Report(sReport(s) and Taking ) and Taking Corrective Action for Unacceptable Corrective Action for Unacceptable Result(sResult(s) in Participating ) in Participating

LaboratoryLaboratory

PROVIDING AND SENDING PROVIDING AND SENDING QC MATERIALQC MATERIAL

••General RequirementsGeneral Requirements••AnalyteAnalyte ValidationValidation••HomogenityHomogenity (Uniformity) Testing(Uniformity) Testing••Stability TestingStability Testing••Stress TestingStress Testing••Shipping TestingShipping Testing

MEASURING ANAYTE(S) MEASURING ANAYTE(S) AND REPORTING AND REPORTING RESULT(S)RESULT(S)

••StorageStorage••ReconstituationReconstituation••Measuring QC Material Like Patient Measuring QC Material Like Patient

SpecimenSpecimen••Reporting Results and Method Characters Reporting Results and Method Characters

1) Kit Producer1) Kit Producer2) Kit Lot No.2) Kit Lot No.3) Procedure3) Procedure

4) Principle of Method4) Principle of Method

REASONS FOR REDUCING REASONS FOR REDUCING CONSISTENCY BETWEEN DIFFERENT CONSISTENCY BETWEEN DIFFERENT METHODS AND PROCEDURES AREMETHODS AND PROCEDURES ARE

••Different Analytical SpecificityDifferent Analytical Specificity••Different Analytical SensitivityDifferent Analytical Sensitivity••Different CalibrationDifferent Calibration••Matrix EffectMatrix Effect

DATA ANALYSIS AND SENDING DATA ANALYSIS AND SENDING EVALUATION RESULT(S)EVALUATION RESULT(S)

••Participants Are Classified ToParticipants Are Classified To1) Total Groups According to 1) Total Groups According to AnalyteAnalyte

2) Peer Groups According to Kit & Method 2) Peer Groups According to Kit & Method

••Statistical Parameters AreStatistical Parameters Are1) Mean (X)1) Mean (X)

2) Standard Deviation (SD)2) Standard Deviation (SD)3) Coefficient of Variation (CV)3) Coefficient of Variation (CV)4) Variance Index Score (VIS)4) Variance Index Score (VIS)

5) Bias Index Score (BIS)5) Bias Index Score (BIS)6) Standard Deviation Index or Interval (SDI)6) Standard Deviation Index or Interval (SDI)

7) Ordinal Comparison for 7) Ordinal Comparison for SemiquatitativeSemiquatitative Results Results

Chosen Coefficient of VariationChosen Coefficient of Variation(CCV)(CCV)

••CCV are the lowest CVs obtained CCV are the lowest CVs obtained for particular determinations for particular determinations during first two years of the during first two years of the

EQASEQAS

••It is kept constant so that It is kept constant so that improvements in the improvements in the

performance of laboratories can performance of laboratories can be detectedbe detected

VIS =

Xlab - Xpeer

Xpeer

CCV%x 100

SDI = Xlab - Xpeer

SDpeer

CV% = SD

Xx 100

INTERPRETATION OF INTERPRETATION OF EVALUATION REPORT(S) AND EVALUATION REPORT(S) AND TAKING CORRECTIVE ACTIONTAKING CORRECTIVE ACTION

••Acceptable Result Means That the Acceptable Result Means That the MethodMethod’’s Result Is Consistent with s Result Is Consistent with

other Laboratories Using the other Laboratories Using the Same Method or PrincipleSame Method or Principle

••For Unacceptable Result, It Is For Unacceptable Result, It Is Necessary to Investigate for Necessary to Investigate for

Possible Cause and Finding the Possible Cause and Finding the Corrective ActionsCorrective Actions

CAUSES FOR EQAP FAILURESCAUSES FOR EQAP FAILURES

••Problem with QC MaterialsProblem with QC Materials1) 1) AnalyteAnalyte UnstabilityUnstability

2) Mishandling of Specimen during 2) Mishandling of Specimen during Shipping to LaboratoryShipping to Laboratory

3) Interfering Substance in QC 3) Interfering Substance in QC MaterialsMaterials

CAUSES FOR EQAP FAILURESCAUSES FOR EQAP FAILURES

••Incorrect Handling of QC Incorrect Handling of QC MaterialsMaterials

1) Incorrect 1) Incorrect ReconstituationReconstituation2) Incorrect Storage Conditions2) Incorrect Storage Conditions3) Evaporation of Prepared QC 3) Evaporation of Prepared QC

MaterialsMaterials

CAUSES FOR EQAP FAILURESCAUSES FOR EQAP FAILURES

••Technical Problem with a MethodTechnical Problem with a Method1) Calibration Problem1) Calibration Problem

2) Inadequate Maintenance Causing Increased 2) Inadequate Maintenance Causing Increased

ImprecisionImprecision3) Deterioration of Reagents and Other 3) Deterioration of Reagents and Other

ComponentsComponents4) Inadequate Environmental Control In 4) Inadequate Environmental Control In

LaboratoryLaboratory

CAUSES FOR EQAP FAILURESCAUSES FOR EQAP FAILURES

••Incorrect ProcedureIncorrect Procedure1) Incorrect Dilution Process1) Incorrect Dilution Process

2) Incorrect Mixing 2) Incorrect Mixing 3) Incorrect Calculation3) Incorrect Calculation

4) Incorrect Unit4) Incorrect Unit5) Transcription Error5) Transcription Error

CAUSES FOR EQAP FAILURESCAUSES FOR EQAP FAILURES

••Incorrect Laboratory Grouping Incorrect Laboratory Grouping And Falling in Group And Falling in Group OthersOthers

Which Is Compared with Which Is Compared with AlloverAllover

WHAT AREWHAT ARETARGETTARGET VALUEVALUE

& & TRUETRUE VALUE ?VALUE ?

Definitive Method

Reference Method

Field Method

ControlMaterial

InternalQuality

Assurance

Primary ReferenceMaterial

Secondary ReferenceMaterial

MethodValidation& External

QualityAssurance

MethodValidation

True Value

Observed Value

Traceability

STRUCURE OF ACCURACY –BASED

SYSTEM

TARGET VALUETARGET VALUE

••Is The Mean of All Results or the Is The Mean of All Results or the Mean of Results from Peer Mean of Results from Peer

LaboratoriesLaboratories••Is Used for Comparison With The Is Used for Comparison With The

Individual LaboratoryIndividual Laboratory’’s Result By s Result By Different Statistical Parameters Different Statistical Parameters

Such As Such As VISVIS And And SDISDI

Peer GROUP PROGRAMPeer GROUP PROGRAM

••Peer Group Program Is A Combination Peer Group Program Is A Combination of of InternalInternal And And ExternalExternal Quality ControlQuality Control

••When EQC Is Used In Conjunction With When EQC Is Used In Conjunction With Daily IQC, This Program Will Give Daily IQC, This Program Will Give

Laboratories Laboratories Added ConfidenceAdded Confidence in Their in Their Patient Test ResultsPatient Test Results

••All Labs Use The Same Control Material All Labs Use The Same Control Material and Report Their Results and Report Their Results DailyDaily

••Data Are Analyzed And Reported Data Are Analyzed And Reported MonthlyMonthly As As SDISDI and and CVRCVR