實驗診斷學(xué)(英文版)第一章

Chapter1

GeneralofClinicalLaboratoryLIPing第1頁，共36頁。GeneralofclinicallaboratoryPrinciplestoclinicallaboratoryTheinterpretationoflaboratorytestsTheethicalpractice第2頁，共36頁。Principletoclinicallaboratory

ResponsibilitiesCollectionofInformationCollectionofSpecimens(Informedconsent、Adequateprivacy)

PerformanceofTestReportingofResultStorageandRetentionofMedicalRecordsAccesstoMedicalRecords第3頁，共36頁。Responsibilities

Thepatient----assurancethequalityandintegralityoftheserviceColleagueandprofessional-----maintainprofessionalreputation,aimtocontributetheadvancementofprofessionSociety----contributetothegeneralwell-beingofsociety;complywithrelevantlawsandregulationsofprofessionalactivities.第4頁，共36頁。Collectionofinformation

IdentifyadequatelypatientsandspecimensEnablethetesttobecorrectlyinterpreted

Otherlegitimatepurposes

第5頁，共36頁。PerformanceofthetestAccreditationprogramPatientsinterestsProcessstandardWorkswithhighskillandcompetence

Goodperformanceoftests

第6頁，共36頁。ReportingofResult

Testresultsareconfidentialunlessdisclosureisauthorized.ReporttheresultscorrectlyandtimelyProvidetheconsultationabouttheselectionandinterpretationoftestsproperly第7頁，共36頁。AccesstoMedicalRecordsclinicianrequestingthetest;thepatient;laboratoryandhospitalstaffifrequiredforthemanagementofthepatient;otherauthorizedindividuals.Whenarequestismadeforaccesstotestresultsbyanauthorizedperson,thelaboratorymustfirstsatisfyitselfasto

theidentityofthepersonmakingtherequest.Who??第8頁，共36頁。

INTERPRETLABORATORYTEST

Selecttest

Patientsprepareforsampling

Collectspecimen

Pre-processofspecimen

Analyzespecimen

Check、reportresult

MakeclinicaldecisionBiologicalvariability,improperorinconsistentpreparation

ImproperorinconsistantCollection

Improperprovision

suboptimumselection

Analyticalvariabilty

InadequateRVs

MinimizevariabilityNoconfusionandmisunderstandingabouttestresultsTestingCycle第9頁，共36頁。Biologicvariatinon

Endogenousbiorhythmsforphysiologicparameters

Differentconstitutionalfactorsandlifestyleamongsubjects

within-subjectvariation

subject-to–subjectvariation

BiologicalvariationWidthofthetest’sReferencinterval(RI)thediagnosticefficiencyofalaboratorytest

BiologicalrhythmsConstitutionalfactorsExtrinsicfactors第10頁，共36頁。ThreetypesofBiologicalrhythmsCircadianRhythmsUltradianRhythmsInfradianRhythmsCycletime24h<24h>24hCharacterConsistentPredictableInconsistentUnpredictableunknowsolutionrhythm-adjustedRVsstimulationandsuppressiontestsunknowexampleNumberandactivityofbloodcellgonadalhormonemenstrualcycle第11頁，共36頁。Biologicvariation

endogenousbiorhythmsforphysiologicparameters

Differentconstitutionalfactorsandlifestyleamongsubjects

within-subjectvariation

subject-to–subjectvariation

BiologicalvariationWidthofthetest’sReferencinterval(RI)thediagnosticefficiencyofalaboratorytest

BiologicalrhythmsConstitutionalfactorsExtrinsicfactors第12頁，共36頁。Biologicvariabilty——

Constitutionalfactorinfants

children

adults

elderly

rapidphysiologicchanges

、hemolysis、bilirubin

Plasmaproteinenzymesexhormonesconstantuntilmenopauseinwomenandmiddleageinmenage-relateddifferencesinnutrition、intercurrentdisease

AgespecificreferencelimitsageAge第13頁，共36頁。Biologicvariabilty–

ConstitutionalfactorGeneticheterogeneity

phenotypicdifferences

DifferentconcentrationofanalyteDifferentreactivitytowardsnucleicacidprobesandantibodiesfalse-negative

MisleadingGeneticheterogeneity第14頁，共36頁。Biologicvariabilty-

ExtrinsicFactorsvascular

interstitialspace

supine

stand

H2OSmallanalyte

plasmavolumeConcentrationofnondiffusiblanalytehomeostasisofvasculartone

renninaldosteronecatecholamines

Posture

第15頁，共36頁。Biologicvariabilty–

ExtrinsicFactorsshiftsinplasmawaterglomerularfiltrationrateurineproductionreleaseofmacromoleculesfromcellsandtissuesExercise

第16頁，共36頁。Biologicvariabilty-

ExtrinsicFactors

mealrelatedfastingrelated

Recommendation:durationoffastingbeforespecimencollectionistypically12hoursTGTCBUNGLU……..LacAcetoneGlucagons……….

Diet第17頁，共36頁。Biologicvariabilty–

ExtrinsicFactors

TypesofInterference——AnalyticalinterferencePhysiologicinterferenceRecommendation——Recognizedrugs’potentialforoccurrence,withdrawmedicationsbeforesamplingwheneverpossible,Evaluatanysuspiciousresultsinlightofasubject’smedicationhistory.Drug第18頁，共36頁。Biologicvariabilty-

ExtrinsicFactorsplasmavolume

erythrocytemass

plasmaproteinsynthesis

altereddistributionofcardiacoutput

endocrinologicchanges

hyperventilationPregnancy第19頁，共36頁。Biologicvariation-summaryBiologicalrhythms——Circadian,Ultradian,InfradianrhythmsConstitutinalfactors——Gender,age,geneExtrinsicfactors——

Posture,Exercise,Diet,Drugs,Pregnancy,Caffeine,Alcoholuse,OralContraceptives,IntercurrentIllness第20頁，共36頁。

EstablishandvalidateRVs

EstablishclinicalperformancecharacteristicsWhy?HelpcliniciantoselectthemosteffectivetestsandtestingstrategiesHelpcliniciantotranslatelaboratoryresultsintoaprobabilitystatementHelpthelaboratorydirectortofocustheresourcesofthelaboratoryontestswiththehighestclinicalrelevanceHow?Collectdata

phaseIIandphaseIIIclinicaltrials第21頁，共36頁。EstablishandvalidateRVs

Howtoassurethevalidityoftheparametersderivedfromclinicaltrials?Usegoldstandardtodefineeverysubject’sstatusAbroadspectrumofhealthyanddiseasedsubjects,includepatientswithawiderangeofclinicalpresentations.CIsshouldbecalculatedforalltheparametersthatareestimated.Whennewtestcompareswiththeoldtest,assuresampleofpatientslargeenoughanddataexactly.???第22頁，共36頁。SensitivityandSpecificityDiseasestatus

TestresultTotalPositivenegativeDiseaseTPFNTP+FNHealthyFPTNFP+TNTotalTP+FPFN+TNTP+FP+TN+FN第23頁，共36頁。SensitivityandSpecificity

Expresstheprobabilitythatadiseasedsubjectwillhaveanabnormalresult

ExpresstheprobabilitythatanondiseasedpatientwillhavearesultwithintheRISensitivity(Se)=TP/(TP+FN)Specificity(Sp)=TN/(TN+FP)

第24頁，共36頁。PredictiveValue

Theprobabilitythatasubjectwithapositivetestresulttrulyhasthedisease

Theprobabilitythatasubjectwithanegativetestresulttrulyishealthy.

PVsareonlyaccuratewhenthetestisappliedtopopulationswithadiseaseprevalencethatissimilartothatofthestudysample.PV+=TP/(TP+FP)PV-=TN/(TN+FN)Note

第25頁，共36頁。ROCCurves

WhatisROCcurveusedfor?Determinethemostefficientdecisionthresholdorcutoffvalueforalaboratorytest.Comparetherelativeclinicalaccuraciesofdifferentlaboratorytestsinaparticularclinicalsetting??第26頁，共36頁。ROCCurves第27頁，共36頁。LikelihoodRatiosLHRexpresstheprobabilitythataparticularwilloccurinadiseasedsubjectdividedbytheprobabilitythatthesameoutcomewilloccurinanondiseasedsubject.

Forcontinousvariabletest,LHRscanbeestablishedfordifferentrangesoftestresults,sothemagnitudeofatestresultprovidesadditionaldiscriminatorypower

LHR+=Se/(1-Sp)=TPrate/FPrate

LHR-=(1-Se)/Sp=FNrate/TNrate第28頁，共36頁。LikelihoodRatios

TPraterepresentbenefitofthetest,FPraterepresentsthecostsassociatedwithtesting,soLHR+representsacost-benefitratio.ItissimilartoLHR-.TheLHR+andLHR-allowthedirectestimationoftheposttestprobabilityofdiseaseinviewofthenewinformationcontributedbythetestresult.LHR+=TPrate/FPrate第29頁，共36頁。LikelihoodRatiosLHRallowtheinformationfromdifferentmodalitiestobecombinedinserialdiagnosticschemesor“criticalpathways”forwhichoverallpredictivevaluescanbecalculated.第30頁，共36頁。EstimatingLHRfromROCCurves

LHRsforaparticulartestcanalsobeobtaineddirectlyformaROCcurvebyevaluatingtheslopesofthecurveindifferentregions

continuousvariabletestpositive/negativetesttestthatclassifiedintomorethantwointervals第31頁，共36頁。ETHICALPRACTICE

Ethicalpracticecanberegardedasappropriatetechnicalpracticeaccompaniedbyintegrityinattitudesandbehavior.

Medicallaboratoryservicesareanintegralpartofmedicalservices,Thesamestandardsandethicalprinciplesthatgovernthedeliveryofclinicalserviceswillalsoapplytothedeliveryoflaboratoryservices.DefinitionsWhyDoWeNeedEthics?第