C24-Ed4统计品质控制

4thEdition

CLINICALAND

LABORATORY

STANDARDS

INSTITUTE'

C24

tatisticalQualityControlforQuantitativeMeasurementProcedures:Principlesand

Definitions

Tisguidelineprovidesdeninitions,pinciples,andapproaches

tBhoratoryqualitycontroldesign,implementation,and

assessment.

AguidelineforglobalapplicationdevelopedthroughtheClinicalandLaboratoryStandardsInstituteconsensusprocess.

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C24,4thedSeptember2016

ReplacesC24-A3

StatisticalQualityControlforQuantitativeMeasurementProcedures:

PrinciplesandDefinitions

CurtisA.Parvin,PhD

NilsB.Person,PhD,FACB

NikolaBaumann,PhD

LiliDuan,PhD

A.PaulDurham

ValerioM.Genta,MD

JeremieGras,MD

GregMiller,PhD

MeganE.Sawchuk,MT(ASCP)

Abstract

ClinicalandLaboratoryStandardsInstituteguidelineC24—StatisticalQualityControlforQuantitativeMeasurementProcedures:PrinciplesandDefinitionsdiscussestheprinciplesofstatisticalQC,withparticularattentiontotheplanningofaQCstrategyandtheapplicationofstatisticalQCinamedicallaboratory.Althoughtheseprinciplesareofinteresttomanufacturers,thisguidelineisintendedforusebymedicallaboratorypersonnelinordertoprovideaQCstrategythatusescontrolmaterialsthatareexternaltoareagentkit,instrument,ormeasuringsystemandthatareintendedtosimulatethemeasurementofapatientspecimen.

ClinicalandLaboratoryStandardsInstitute(CLSI).StatisticalQualityControlforQuantitativeMeasurementProcedures:

PrinciplesandDefinitions.4thed.CLSIguidelineC24(ISBN1-56238-946-7[Print];ISBN1-56238-947-5[Electronic]).Clinical

andLaboratoryStandardsInstitute,950WestValleyRoad,Suite2500,Wayne,Pennsylvania19087USA,2016.

TheClinicalandLaboratoryStandardsInstituteconsensusprocess,whichisthemechanismformovingadocumentthroughtwoormorelevelsofreviewbythehealthcarecommunity,isanongoingprocess.Usersshouldexpectrevisededitionsofanygivendocument.Becauserapidchangesintechnologymayaffecttheprocedures,methods,andprotocolsinastandardorguideline,usersshouldreplaceoutdatededitionswiththecurrenteditionsofCLSIdocuments.CurrenteditionsarelistedintheCLSIcatalogandpostedonourwebsiteat.Ifyouoryourorganizationisnotamemberandwouldliketobecomeone,andtorequestacopyofthecatalog,contactusat:Telephone:+1.610.688.0100;Fax:+1.610.688.0700;E-Mail:customerservice@;Website:.

CLINICALANDLABORATORY

STANDARDS

INSTITUTE

ii

C24,4thed.

Copyright2016ClinicalandLaboratoryStandardsInstitute.Exceptasstatedbelow,anyreproductionofcontentfromaCLSIcopyrightedstandard,guideline,companionproduct,orothermaterialrequiresexpresswrittenconsentfromCLSI.Allrightsreserved.Interestedpartiesmaysendpermissionrequeststopermissions@.

CLSIherebygrantspermissiontoeachindividualmemberorpurchasertomakeasinglereproductionofthispublicationforuseinitslaboratoryproceduresmanualatasinglesite.Torequestpermissiontousethispublicationinanyothermanner,e-mailpermissions@.

SuggestedCitation

CLSI.StatisticalQualityControlforQuantitativeMeasurementProcedures:PrinciplesandDefinitions.

4thed.CLSIguidelineC24.Wayne,PA:ClinicalandLaboratoryStandardsInstitute;2016.

PreviousEditions:

March1985,September1986,May1991,February1999,June2006

ISBN1-56238-946-7(Print)

ISBN1-56238-947-5(Electronic)

ISSN1558-6502(Print)

ISSN2162-2914(Electronic)Volume36,Number

12

iii

CommitteeMembership

ConsensusCouncil

CarlD.Mottram,RRT,RPFT,

FAARC

Chairholder

MayoClinic

USA

J.RexAstles,PhD,FACB,DABCCCentersforDiseaseControland

Prevention

USA

LuciaM.Berte,MA,MT(ASCP)SBB,DLM;CQA(ASQ)CMQ/OE

LaboratoriesMadeBetter!

USA

KarenW.Dyer,MT(ASCP),DLMCentersforMedicare&Medicaid

Services

USA

DennisJ.Ernst,MT(ASCP),

NCPT(NCCT)

CenterforPhlebotomyEducation

USA

ThomasR.Fritsche,MD,PhD,FCAP,

FIDSA

MarshfieldClinic

USA

MaryLouGantzer,PhD,FACB

BioCoreDiagnostics

USA

LoralieJ.Langman,PhD

MayoClinic

USA

JosephPassarelli

RocheDiagnosticsCorporation

USA

C24,4thed

JamesF.Pierson-Perry

SiemensHealthcareDiagnosticsInc.USA

AndrewQuintenz

Bio-RadLaboratories,Inc.

USA

RobertRej,PhD

NewYorkStateDepartmentof

Health-WadsworthCenter

USA

ZivanaTezak.PhD

FDACenterforDevicesand

RadiologicalHealth

USA

DocumentDevelopmentCommitteeonStatisticalQCforClinicalChemistry

CurtisA.Parvin,PhD

LiliDuan,PhD

GregMiller,PhD

Chairholder

FDACenterforDevicesandRadiological

VirginiaCommonwealthUniversity

Bio-RadLaboratories,Inc.

Health

HealthSystem

USA

USA

USA

NilsB.Person,PhD,FACB

JeremieGras,MD

MeganE.Sawchuk,MT(ASCP)

Vice-Chairholder

CliniqueSt.Luc

CentersforDiseaseControland

SiemensHealtheareDiagnostics,Inc.

Belgium

Prevention

USA

USA

NikolaBaumann,PhD

MayoClinic

USA

Staff

ClinicalandLaboratoryStandards

JoanneP.Christopher,MA,ELS

Institute

Editor

USA

LauraMartin

LuannOchs,MS

Editor

ProjectManager

MichaelA.Russell,MA

MeganL.Tertel,MA,ELS

Editor

EditorialManager

C24,4thed.

AcknowledgmentfortheExpertPanelonClinicalChemistryandToxicology

CLSI,theConsensusCouncil,andtheDocumentDevelopmentCommitteeonStatisticalQCforClinicalChemistrygratefullyacknowledgetheExpertPanelonClinicalChemistryandToxicologyforservingastechnicaladvisorsandsubjectmatterexpertsduringthedevelopmentofthisguideline.

ExpertPanelonClinicalChemistryandToxicology

JohannaCamara,PhD

LiliDuan,PhD

GodwinOgbonna,PhD

Chairholder

FDACenterforDevicesand

Ortho-ClinicalDiagnostics,Inc.

NationalInstituteofStandardsand

RadiologicalHealth

USA

Technology

USA

USA

CurtisOleschuk,PhD,FCACB

KamishaJohnson-Davis,PhD,

DiagnosticServicesofManitoba

LorinM.Bachmann,PhD,DABCC

DABCC,FACB

Canada

Vice-Chairholder

UniversityofUtahandARUP

VirginiaCommonwealthUniversity

Laboratories

DavidB.Sacks,MB,ChB,FRCPath

HealthSystem

USA

NationalInstitutesofHealth

USA

USA

GregoryT.Maine,PhD,FACB

KarlDeVore

Abbott

Bio-RadLaboratories,Inc.

USA

USA

Acknowledgment

CLSI,theConsensusCouncil,andtheDocumentDevelopmentCommitteeonStatisticalQCforClinicalChemistrygratefullyacknowledgethefollowingvolunteersfortheirimportantcontributionstothedevelopmentofthisguideline:

A.PaulDurham

APDConsulting

USA

ValerioM.Genta,MD

SentaraVirginiaBeachGeneralHospital

USA

iv

V

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Contents

Abstract i

CommitteeMembership iii

Foreword vii

Chapter1:Introduction

1

1.1Scope

1

1.2Background

2

1.3StandardPrecautions

2

1.4Terminology

3

Chapter2:PathofWorkflow

9

Chapter3:PurposeofStatisticalQualityControl

11

3.1QualityControlandPatientRisk

11

3.2QualityRequirements

12

3.3MethodPerformanceRelativetoQualityRequirements

14

3.4TypesofOut-of-ControlConditions

17

3.5QualityControlRules

17

Chapter4:AssessingQualityControlPerformance

19

4.1FalseRejectionRate

19

4.2DetectionofOut-of-ControlConditions

20

Chapter5:PlanningaStatisticalQualityControlStrategy

23

5.1DefinetheQualityRequirements

23

5.2SelectControlMaterials

24

5.3DetermineTargetValuesandStandardDeviationsforQualityControlMaterials

ThatRepresentStableAnalyticalPerformance

27

5.4SetGoalsforQualityControlPerformance

31

5.5SelectaQualityControlStrategyBasedonPerformanceGoals

32

5.6DesignaQualityControlStrategyforMultipleInstruments

37

Chapter6:RecoveringFromanOut-of-ControlCondition

39

6.1RespondingtoanOut-of-ControlQualityControlEvent

39

6.2RespondingtoanOut-of-ControlCondition

39

6.3IdentifyingandCorrectingReportedErroneousPatientResults

39

Chapter7:OngoingAssessmentofQualityControlPrograms

41

7.1AssessmentoftheInternalQualityControlProgram

41

7.2UsingInterlaboratoryQualityControltoAssessaQualityControlProgram

41

Chapter8:WorkedExamples

43

8.1DefinetheQualityRequirement

43

8.2SelectQualityControlMaterials

43

8.3DetermineTargetValuesandStandardDeviations

43

8.4SelectQualityControlStrategy

44

Chapter9:Conclusion

46

Chapter10:SupplementalInformation

46

References

47

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Contents(Continued)

AppendixA.Levey-JenningsChart

50

AppendixB.MedicalLaboratoryQualityControlShiftandTrendTroubleshooting

Checklist

55

TheQualityManagementSystemApproach

60

RelatedCLSIReferenceMaterials

61

vi

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Foreword

ThemedicallaboratorycommunityhasusedC24,nowinitsfourthedition,formorethan20years.Today,statisticalQCisstillcriticallyimportanttoensurethequalityoftheresultsofanylaboratorymeasurementprocedure.ThealmostuniversalapplicabilityofstatisticalQCtoquantitativemeasurementproceduresprovideslaboratorieswithanessentialqualitymanagementtoolthatcanbeusedtomonitortheeffectsofmanyinstrument,reagent,environment,andoperatorvariablesontheoutcomeofameasurementprocess.

ThelaboratorydirectorisgenerallyresponsibleforthelaboratoryQCprogram.Thedefinitionofqualityrequirementsforthetestsbeingperformedisparticularlyimportantbecauselaboratorymanagers,supervisors,scientists,andqualityspecialistsoftenusethosequalityrequirementstoselectandvalidateappropriatemeasurementandcontrolprocedures.C24'sapproachprovidesmedicallaboratoryscientistswithpracticalguidanceonhowtosatisfyrecommendationsbyauthoritiesand/oraccreditationorganizations.

Theconcepts,approaches,andpracticesdiscussedinthisguidelineareinterdependentandallshouldbecarefullystudiedandconsideredwhendevelopingthespecificQCstrategyforanymeasurementprocedure,system,orlaboratory.C24highlightsthetechnicalissuesthatneedacarefulscientificapproachtodesigning,implementing,andassessingQCstrategiesinorderforlaboratoriestoachievethequalityrequirementsneededbythephysiciansandpatientstheyserve.

OverviewofChanges

Thisguidelinereplacesthepreviouseditionoftheapprovedguideline,C24-A3,publishedin2006.ThefourtheditionmaintainsthefocusonprinciplesandapproachestolaboratoryQCdesign,implementation,andassessmentthatreflecttherealitiesofthemodernmedicallaboratoryanditsrolewithinthehealthcareenterprise.Severalchangesweremadeinthisedition,including:

·ThealignmentofprinciplesanddefinitionstobeconsistentwithandtosupplementthegeneralpatientriskmodeldescribedinCLSIdocumentEP23TM²

·TheintroductionofadditionalperformancemeasuresusefulforevaluatingtheperformancecharacteristicsofaQCstrategy(seeChapter5)

·ExpandedguidanceonsettingtargetvaluesandSDsforQCmaterials(seeSubchapter5.3)

·AgreaterfocusonQCfrequencyandQCschedulesasacriticalpartofaQCstrategy(seeSubchapter5.5)

Asubstantivechapteronrecoveringfromanout-of-controlcondition(seeChapter6),including

sectionson:

-Respondingtoanout-of-controlQCevent

-Respondingtoanout-of-controlcondition

-Identifyingandcorrectingreportederroneouspatientresults

NOTE:ThecontentofthisguidelineissupportedbytheCLSIconsensusprocess,anddoesnotnecessarilyreflecttheviewsofanysingleindividualororganization.

KeyWords

Patientrisk,qualitycontrol,qualitycontrolplan,qualitycontrolrules,qualitycontrolstrategy,qualityrequirements,Sigmametric

vii

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StatisticalQualityControlforQuantitativeMeasurementProcedures:PrinciplesandDefinitions

Chapter1:Introduction

Thischapterincludes:

·Guideline'sscopeandapplicableexclusions

●Backgroundinformationpertinenttotheguideline'scontent

·Standardprecautionsinformation

·“NoteonTerminology”thathighlightsparticularuseand/orvariationinuseoftermsand/or

definitions

·Termsanddefinitionsusedintheguideline

·Abbreviationsandacronymsusedintheguideline

1.1Scope

ThisguidelineexplainsthepurposeofstatisticalQCforquantitativemeasurementprocedures,describesanapproachforplanningaQCstrategyforaparticularmeasurementprocedure,describestheuseofQCmaterialandQCdata,andprovidesexamplesthatdemonstrateapracticalQCplanningprocessformedicallaboratories.

TherecommendationsforestablishingandmaintainingastatisticalQCstrategyareapplicabletoquantitativelaboratorymeasurementproceduresinallfieldsoflaboratorymedicineforwhichstablecontrolmaterialscanbemeasuredinthesamemanneraspatientspecimens.Theintendedusersofthisguidelineincludethoseresponsiblefordesigning,implementing,andusingQC,ie,medicallaboratoryscientists.

Thisguidelinedoesnot:

·Describebuilt-incontrolmechanismsthatmightbepartofameasuringsystem,orqualitativeorsemiquantitativemeasurementprocedures.

·DefinespecificQCstrategiesthatareappropriateforanindividualdeviceortechnology.

·Describealternativestostatisticalprocesscontrol,eg,real-timepatient-basedQC.

·ConsiderspecificlegalrequirementsthatmayimposedifferentphilosophiesorproceduresonQCpractices(eg,aspecificapproachfordefiningqualityrequirements,specificvaluesforqualityrequirements,aspecificprocedurefordeterminingtargetvaluesforcontrolmaterials,orafrequencyandnumberofQCmeasurements)definedbygovernmentregulationinaspecificcountryorregion.

Additionally,therearetypesofrandomerrorsthatmayaffectmeasurementsperformedonindividualspecimens,ratherthanawholegroupofspecimens,andthoseerrorsarenotdetectedbyastatisticalQCstrategy.Sucherrorsmaybeduetothespecificdesignofameasuringsystem(eg,effectofspecimen

◎ClinicalandLaboratoryStandardsInstitute.Allrightsreserved.1

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viscosity,carryoverfromapreviousspecimen,orspecimen-specificinterferences)orpossibleoperatorerrorsthataffectindividualspecimens,aswellaspreexaminationerrorsofspecimenpreparation,storage,andtransportation.SpecialQCstrategiesmaybeneededtomonitorknownspecialvulnerabilitiesthatrelatetoaparticulardeviceorsystemdesign.

1.2Background

StatisticalQCstrategiesareimplementedtomonitorameasurementprocedure'sperformancetodetectanychangerelativetostablebaselineanalyticalperformance.Whentheactualperformancedeviatesfromtheexpectedmodel,theQCstrategyisdesignedtoalertthelaboratoriantoachangethatmayaffectmedicaldecisionmakingandpotentiallyleadtoincorrecttreatment,delaysintreatment,orpatientharm.DesigninganeffectiveQCstrategyentailsdeterminingthemagnitudeofthechangeinperformancethatcompromisestheusefulnessofthemeasurementprocedureresults.

ThereisabundantliteratureexplainingthetheoreticalandpracticalbasesforinitiatingandmaintainingQCstrategiesinclinicalchemistry³;however,theroutinepracticeofstatisticalQCdependsonunderstandinghowto:

·PlanQCstrategiesbasedontheperformanceofthemeasurementprocedureandtheperformanceneededtosupporttheintendedmedicaluseoftheresults,includingselectingappropriatecontrolmaterials,establishingtheexpectedvaluesforthosecontrolmaterials,determiningwhentoevaluatecontrols,andidentifyingthecontrolrulestodetermineacceptableperformance.

·ImplementQCstrategiestoidentifysituationswhenameasurementproceduremaynotbeproviding

resultsthataresuitableforuseinmedicaldecisions.

·Respondtoout-of-controlsituations.

TheprevalenceofabroadrangeofautomatedmedicallaboratoryinstrumentsusingwidelydifferentmeasuringprincipleshascomplicatedtheterminologyandthestepsnecessaryforestablishingQCstrategies.Therearesomehighlyautomatedsystemsthatcanperformspecific,built-inchecksthathelpdetectpotentialproblemsandalerttheoperatortoinstrumentmalfunction.However,thebenefitofstatisticalQCusingsamplesintendedtosimulatemeasurementofpatientspecimensisthatitmonitorstheoutcomeofmanyofthevariablesandstepsthatoccurintheentiremeasurementprocedure.

1.3StandardPrecautions

Becauseitisoftenimpossibletoknowwhatisolatesorspecimensmightbeinfectious,allpatientandlaboratoryspecimensaretreatedasinfectiousandhandledaccordingto"standardprecautions."Standardprecautionsareguidelinesthatcombinethemajorfeaturesof"universalprecautionsandbodysubstanceisolation”practices.Standardprecautionscoverthetransmissionofallknowninfectiousagentsandthusaremorecomprehensivethanuniversalprecautions,whichareintendedtoapplyonlytotransmissionofbloodbornepathogens.Publishedguidelinesareavailablethatdiscussthedailyoperationsofdiagnosticmedicineinhumansandanimalswhileencouragingacultureofsafetyinthelaboratory.!0Forspecificprecautionsforpreventingthelaboratorytransmissionofallknowninfectiousagentsfromlaboratoryinstrumentsandmaterialsandforrecommendationsforthemanagementofexposuretoallknowninfectiousdiseases,refertoCLSIdocumentM29.!!

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1.4Terminology

1.4.1ANoteonTerminology

CLSI,asagloballeaderinstandardization,isfirmlycommittedtoachievingglobalharmonizationwheneverpossible.Harmonizationisaprocessofrecognizing,understanding,andexplainingdifferenceswhiletakingstepstoachieveworldwideuniformity.CLSIrecognizesthatmedicalconventionsintheglobalmetrologicalcommunityhaveevolveddifferentlyindifferentcountriesandregions,andthatlegallyrequireduseofterms,regionalusage,anddifferentconsensustimelinesareallimportantconsiderationsintheharmonizationprocess.CLSIrecognizesitsimportantroleintheseefforts,anditsconsensusprocessfocusesonharmonizationoftermstofacilitatetheglobalapplicationofstandardsandguidelines.

1.4.2Definitions

accuracy(ofmeasurement)-closenessofagreementbetweenameasuredquantityvalueandatruequantityvalueofameasurandl²;NOTE1:Theconcept"measurementaccuracy"isnotaquantityandisnotgivenanumericalquantityvalue.Ameasurementissaidtobemoreaccuratewhenitoffersasmallermeasurementerror²;NOTE2:Theterm“measurementaccuracy”shouldnotbeusedformeasurementtruenessandtheterm“measurementprecision"shouldnotbeusedfor"measurementaccuracy”,which,however,isrelatedtoboththeseconcepts'2;NOTE3:“Measurementaccuracy"issometimesunderstoodasclosenessofagreementbetweenmeasuredquantityvaluesthatarebeingattributedtothemeasurand.!2

allowabletotalerror(TEa)-ananalyticalqualitygoalthatsetsalimitforboththeimprecision(randomerror)andbias(systematicerror)thataretolerableinasinglemeasurementorsingletestresult;NOTE1:Forqualitycontrol(QC)planning,itisassumedtherearenospecimen-specificinfluencesbecausetheyareacomponentofoverallmethodperformancethatisnotmonitoredbyastatisticalQCstrategy;NOTE2:Somepublicationsdenoteallowabletotalerroras“ATE.”

analyte-constituentofasamplewithameasurableproperty³;NOTE:In“massofproteinin24-hoururine,”"protein"istheanalyteand“mass”istheproperty.In“concentrationofglucoseinplasma,"“glucose”istheanalyteand"concentration"istheproperty.Inbothcases,thefullphraserepresentsthe

measurand.13

bias(ofmeasurement)-estimateofasystematicmeasurementerrorl²;differencebetweentheexpectationofatestresultormeasurementresultandatruevalue'4;NOTE1:Inpractice,theacceptedreferencevalueissubstitutedforthetruevalue'4;NOTE2:Biasrepresentsthequantitativeexpressionoftrueness.

coefficientofvariation(CV)-(positiverandomvariable)standarddeviation(SD)dividedbythemean'5;NOTE1:TheCViscommonlyreportedasapercentage'5;NOTE2:Thepredecessorterm"relativeSD"isdeprecatedbythetermCV.

controllimit-themostextremevalueofaqualitycontrolmaterialthatisstillconsideredtobeacceptable.

erroneousresult-apatientresultthatfailsitsqualityrequirement;NOTE1:Thequalityrequirementisusuallyexpressedintermsofanallowabletotalerror(TEa)requirement.Ifthemeasurementerrorinapatient'sresultexceedstheTEarequirement,theresultiserroneous;NOTE2:Mayalsobereferredtoasanincorrectresultoranunacceptableresult.

error(ofmeasurement)-measuredquantityvalueminusareferencequantityvalue'?;NOTE1:Theconceptof"measurementerror"canbeusedbotha)whenthereisasinglereferencequantityvaluetoreferto,whichoccursifacalibrationismadebymeansofameasurementstandardwithameasuredquantityvaluehavinganegligiblemeasurementuncertaintyorifaconventionalquantityvalueisgiven,inwhichcasethemeasurementerrorisknown,andb)ifameasurandissupposedtoberepresentedbyauniquetrue

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quantityvalueorasetoftruequantityvaluesofnegligiblerange,inwhichcasethemeasurementerrorisnotknown'²;NOTE2:Measurementerrorshouldnotbeconfusedwithproductionerrorormistake.!2

imprecision-therandomdispersionofasetofreplicatemeasurementsand/orvaluesexpressedquantitativelybyastatistic;NOTE:Itisexpressednumericallyasstandarddeviationorcoefficientofvariation.

mean(arithmetic)//average-sumofrandomvariablesinarandomsampledividedbythenumberoftermsinthesum'5;NOTE:Thesamplemeanconsideredasastatisticisoftenusedasanestimatorforthepopulationmean.Acommonsynonymisarithmeticmean.5

measurand-quantityintendedtobemeasured²;NOTE1:Thespecificationofameasurandrequiresknowledgeofthekindofquantity,descriptionofthestateofthephenomenon,body,orsubstancecarryingthequantity,includinganyrelevantcomponent,andthechemicalentitiesinvolved;NOTE2:InthesecondeditionoftheVIM²andinIEC60050-300:2001,themeasurandisdefinedasthe"particularquantitysubjecttomeasurement”|2;NOTE3:Themeasurement,includingthemeasuringsystemandtheconditionsunderwhichthemeasurementiscarriedout,mightchangethephenomenon,b