实验流行病学文献评阅PPT课件

.,1,实验流行病学文献评阅,曾芳芳流行病学教研室,.,2,A.Descriptionoftheevidence证据的描述,Whatwasthestudydesignandhowtocollectdataweneed?Whatwasthestudypopulation?Whatwastheexposure?Whatwastheoutcome?Whatwasthemainresult?,.,3,B.Internalvalidityconsiderationofnon-causalexplanations内部真实性考虑是否有非因果解释,Aretheresultslikelytobeaffectedbyselectionbias?是否由于选择偏移所致Aretheresultslikelytobeaffectedbyobservationbias?是否由于观察偏移所致Aretheresultslikelytobeaffectedbyconfounding?是否由混杂偏移所致Aretheresultslikelytobeaffectedbychancevariation?是否出于偶然因素,.,4,C.Internalvalidityconsiderationofpositivefeaturesofcausation内部真实性因果关系阳性特征的考虑,1.Isthereacorrecttimerelationship?是否存在前因后果的时间关系2.Istherelationshipstrong?联系强度3.Isthereadose-responserelationship?是否存在剂量反应关系？Aretheresultsconsistentwithinthestudy?不同的相关研究指标结果是否一致5.Isthereanyspecificitywithinthestudy?研究是否存在特异性？,.,5,D.Externalvaliditygeneralizationoftheresults外部特异性结果能否外推,Canthestudyresultsbeappliedtotheeligiblepopulation?结果能否适用于合格研究人群Canthestudyresultsbeappliedtothesourcepopulation?结果能否适用于源人群Canthestudyresultsbeappliedtootherrelevantpopulations?结果是否适用于其他相关人群,.,6,E.Comparisonoftheresultswithotherevidence与其它证据的比较,1.Aretheresultsconsistwithotherevidence,particularlyevidencefromstudiesofsimilarormorepowerfulstudydesign?研究结果是否与其它研究(尤其是设计更好，证据更强的)结果相似或一致？2.Doesthetotalevidencesuggestanyspecificity?研究结果是否存在特异性？3.Aretheresultsplausible,intermsofabiologicalmechanism?研究结果是否合理，能否用生物学机制解释4.Ifamajoreffectisshown,isitcoherentwiththedistributionoftheexposureandtheoutcome?如果存在联系，该联系与人群的暴露与结局分布是否一致？,.,7,TheRevisedCONSORTStatementforReportingRandomizedTrials:ExplanationandElaboration,AnnInternMed.2001Apr17;134(8):663-94.,.,8,INCOMPLETEANDINACCURATEEPORTING,informationonwhetherassessmentofoutcomes*wasblindedwasreportedinonly30%of67trialreportsinfourleadingjournalsin1979and1980only27%of45reportspublishedin1985definedaprimaryendpoint*(14),andonly43%of37trialswithnegativefindingspublishedin1990reportedasamplesize*calculation,.,9,Of119reportsstatingthatallparticipants*wereincludedintheanalysisinthegroupstowhichtheywereoriginallyassigned(intention-to-treat*analysis),15(13%)excludedpatientsordidnotanalyzeallpatientsasallocated,.,10,ChecklistofItemsToIncludeWhenReportingaRandomizedTrial,.,11,TitleandAbstract,Howparticipantswereallocatedtointerventions(e.g.,“randomallocation,”“randomized,”or“randomlyassigned”).,.,12,Introduction,Scientificbackgroundandexplanationofrationale,.,13,Methods-Participants,EligibilitycriteriaforparticipantsThesettingsandlocationswherethedatawerecollected,.,14,Methods-Interventions,Precisedetailsoftheinterventionsintendedforeachgroupandhowandwhentheywereactuallyadministered.,.,15,Methods-Objectives,Specificobjectivesandhypotheses.,.,16,Methods-Outcomes,Clearlydefinedprimaryandsecondaryoutcomemeasures.Whenapplicable,anymethodsusedtoenhancethequalityofmeasurements(e.g.,multipleobservations,trainingofassessors).,.,17,Methods-Samplesize,HowsamplesizewasdeterminedWhenapplicable,explanationofanyinterimanalysesandstoppingrules.,.,18,Methods-Randomization,MethodusedtogeneratetherandomallocationsequenceDetailsofanyrestrictionofrandomization(e.g.,blocking,stratification)Methodusedtoimplementtherandomallocationsequence(e.g.,numberedcontainersorcentraltelephone),clarifyingwhetherthesequencewasconcealeduntilinterventionswereassigned.,.,19,Whogeneratedtheallocationsequence,whoenrolledparticipants,andwhossignedparticipantstotheirgroups.,.,20,Methods-Blinding(masking),Whetherornotparticipants,thoseadministeringtheinterventions,andthoseassessingtheoutcomeswereblindedtogroupassignment.Ifdone,howthesuccessofblindingwasevaluated.,.,21,Methods-Statisticalmethods,Statisticalmethodsusedtocomparegroupsforprimaryoutcome(s).Methodsforadditionalanalyses,suchassubgroupanalysesandadjustedanalyses.,.,22,Results-Participantflow,Flowofparticipantsthrougheachstage(adiagramisstronglyrecommended).Specifically,foreachgroupreportthenumbersofparticipantsrandomlyassigned,receivingintendedtreatment,completingthestudyprotocol,andanalyzedfortheprimaryoutcome.Describeprotocoldeviationsfromstudyasplanned,togetherwithreasons.,.,23,Results-Recruitment,Datesdefiningtheperiodsofrecruitmentandfollow-up.,.,24,Results-Baselinedata,Baselinedemographicandclinicalcharacteristicsofeachgroup,.,25,Results-Numbersanalyzed,Numberofparticipants(denominator)ineachgroupincludedineachanalysisandwhethertheanalysiswasby“intentiontotreat.”Statetheresultsinabsolutenumberswhenfeasible(e.g.,10of20,not50%).,.,26,Results-Outcomesandestimation,Foreachprimaryandsecondaryoutcome,asummaryofresultsforeachgroupandtheestimatedeffectsizeanditsprecision(e.g.,95%confidenceinterval).,.,27,Results-Ancillaryanalyses,Addressmultiplicitybyreportinganyotheranalysesperformed,includingsubgroupanalysesandadjustedanalyses,indicatingthoseprespecifiedandthoseexploratory.,.,28,Results-Adverseevents,Allimportantadverseeventsorsideeffectsineachinterventiongroup.,.,29,Discussion-Interpretation,Interpretationoftheresults,takingintoaccountstudyhypotheses,sourcesofpotentialbiasorimprec