高血压英文课件ProspectiveC

FrederickL.Brancati,MD,MHSProfessorofMedicine&EpidemiologyDirector,DivisionofGeneralInternalMedicineOslerJournalClub2006VisitHopkinsGIMat/gimProspectiveCohortStudies..BackgroundPhysicalactivitylowerCVDriskDHHSrecommendslife-longpursuitsSportsdifferinsustainabilityCVDbenefitsofindividualsportsuncertain.TheJohnsHopkinsPrecursorsStudyOver1300students(mainlywhitemen)fromtheJHUSOMClassesof1948-64.Baselinedatacollectedinpersoninmedicalschool.Follow-updatacollectedbyyearlymailedquestionnairesthereafter..CarolineThomas,MDTheJohnsHopkinsPrecursorsStudy.Hypothesis:TennisabilityinyouthpredictslowerCVDriskinmiddleageDesign:ProspectivecohortstudySetting:JohnsHopkinsPrecursorsStudyParticipants:1019malemedicalstudentsDataCollection:Extensiveinterviewandphysicalassessmentatbaseline(early20s);annualmailedfollow-upquestionnairesOutcome:IncidentCVD,includingMI,CHD,CABGorPTCA,hypertensiveheartdisease,heartfailure,&cerebrovasculardiseaseAnalysis:Kaplan-Meier,CoxmodelsOutline.AssessmentofSportsAbilityHowwouldyourateyouroverallabilityintennis(golf,football,baseball,basketball)duringandbeforemedicalschool?NoabilityPoororfairabilityGoodorexcellentabilityNodataonfrequency,intensity,orsubsequentparticipation.Results......Conclusions/ImplicationsSelf-describedtennisabilityinyoungadulthoodpredictslowerCVDriskinmiddleageAssociationoftennistolowerriskisGraded(i.e.dose-response)IndependentofmanypossibleconfoundersSpecifictotennis(ashypothesized)SuggestspromotionoftennisasameanstoreduceCVDrisk.StrengthsProspectivedesignLong-termfollow-upMultiavariateanalysisBlindedassessmentofCVD.WeaknessesObservationalstudiescan’tprovecausalityResidualconfoundingislikelyAssessmentofexposurewassuboptimalAbility,notactivitySinglepoint,notrepeatedmeasuresSelf-assessed,notobjectiveSamplelimitsgeneralizability.DiscussionPointsWhat’sspecialaboutacohortstudy?Whatarecommonobstacles?Canitbeusedforhousestaffresearch?Caniteverbesufficienttochangepractice?Howdocohortstudiesrelatetooutcomesresearch?.TaxonomyofDesignsRandomizedControlledTrialProspectiveCohortStudyCase-ControlStudyCross-SectionalStudyOtherDesignsQuasi-ExperimentalEcologicCaseReport.Thebasicfightingunitwasacohort,composedofsixcenturies(480menplus6centurions).Thelegionitselfwascomposedoftencohorts,andthefirstcohorthadmanyextramen—theclerks,engineers,andotherspecialistswhodidnotusuallyfight—andtheseniorcenturionofthelegion,theprimipilus,or“numberonejavelin.”.pro·spec·tive

Pronunciation:pr&-'spek-tivalso'prä-",prO-',prä-'

Function:adjective

Date:circa1699

1

:relatingtooreffectiveinthefuture

2a

:likelytocomeabout:EXPECTED<theprospectivebenefitsofthislaw>b

:likelytobeorbecome<aprospectivemother>.“Prospective”inEpidemiologyClearlydefinedcohort(group,sample)ofpersonsatriskfollowedthroughtimeDataregardingexposures(riskfactors,predictors)collectedpriortodataonoutcomes(endpoints)Research-gradedatacollectionmethodsusedforpurposeoftestinghypothesis(?).DiagramofHypothetical6-YearCohortStudytoIdentifyRiskFactorsforFacialAcneinTeenagers100012-year-oldswithoutacne50018-year-oldswithoutacne90015-year-oldswithoutacne50withAcne300withAcne5moved10noanswer35refused10moved40noanswer48refused2deaths350incidentcasesofacneover6years6-yrFollow-upRate=850/1000=85%IncidenceRateofAcne=350/5475PY=63.9per1000PY.WhyDoACohortStudy?GetincidencedataStudyarangeofpossibleriskfactorsEstablishtemporalsequenceGetrepresentativedataPrepareforrandomizedcontrolledtrialEstablisharesearchempire.TypesofCohortsOccupational(e.g.Asbestosworkers)Convenience(e.g.Precursors,Nurses)Geographic(e.g.Framingham,ARIC)DiseaseorProcedureNaturalHistory(e.g.Syncope,Lupus)OutcomesResearch(e.g.Dialysis,Cataracts).SourcesofCohortDataClinicVisitsLaboratoryAssaysInterviewPhysicalExaminationImagingPhysiologictestsHomevisitsMailedmaterialsTelephoneInterviewMedicalRecordsAdministrativeDataMedicareMedicaidManagedCareVeteransAdminBirthRecordsDeathCertificatesSpecimenBank.WilliamCastelli,MDTheFraminghamHeartStudy.RecentlyPublishedStudiesfromtheJohnsHopkinsPrecursorsStudyCoronaryDisease -Anger,Depression,Gout,-SportsAbilityType2Diabetes -Bloodpressure,AdiposityHypertension -CoffeeKneeOsteoarthritis -KneeinjuryDepression -InsomniaOutcomeExposure.WhatMightExplainObservedRelationshipofTennisAbilitytoHeartDiseaseRisk?TennisprotectsagainstheartdiseaseMenwholiketoplaytennisaredifferentThinnerHealthierLifestylesHigherSocioeconomicStatusMenwhoplaytenniswellaredifferentTaller,ThinnerGreaterCardiovascularFitnessChance(typeIerror)–Needsconfirmation.PlaysTennisPlaysTennisWellSustainedActivityThruMidlifeLoweradiposity,GreaterFitnessLowerBP,LowerLDL,HigherHDLLowerRiskofCHDHypotheticalCausalPathwayHealthierMenChooseTennisHealthierMenPlayTennisWel