流行病學(xué)研究方法總結(jié)分析

1、1. 于研究對(duì)象參與研究的過(guò)程中可能會(huì)怎樣做，提高統(tǒng)計(jì)學(xué)功效高A run-in period in a randomized clinical trial (RCT) can be defined as a specified period time after enrollment and prior to1. 于研究對(duì)象參與研究的過(guò)程中可能會(huì)怎樣做，提高統(tǒng)計(jì)學(xué)功效高A run-in period in a randomized clinical trial (RCT) can be defined as a specified period time after enrollment an

2、d prior to participantseligibility and commitmenttoa studyt is allotted to further easure 2.GIS地理信息系GIS真正的功能在于它利用空間分析技術(shù)對(duì)空間數(shù)據(jù)的分析將空間分析應(yīng)用于流行病學(xué)研究, 的、療資源進(jìn)行有效的配置。然而, 從整體上看, 空間分析在流行病學(xué)研究中的應(yīng)用完善之處, 并且長(zhǎng)期以來(lái)積累的流行病學(xué)數(shù)據(jù)缺乏空間屬性, 這些都限制了空間GIS在疾病控制和流行病學(xué)中的應(yīng)用包括：疫病流行專題地圖的繪制3.Zelens“randomising patients before consent to pa

3、rticipate has been sought”. Two types of design exist: double and single he double consent patients are initially the treatment to which they were randomised; however, if they decline the randomised they can then be offered alternative including the experimental he consent only patients offered the

4、experimental treatment are told there treatment (the control) available. Patients randomised to the control treatment are not allowed experimental treatment (although they are given unhindered s to any usual ysisisundertakenwithpatientsretainingtheiroriginalThere are obvious ethical problems in usin

5、g Zelens design to randomise patients their consent8(though treatment consent is always sought). For erventions,however,as screening, this may be the only practical design. For le, if all he cancer screening trials had been screened but only a random half had been there would have as screening, this

6、 may be the only practical design. For le, if all he cancer screening trials had been screened but only a random half had been there would have been an ethical dilemma of not offering further investigation and treatment controlpatientswhoappeared tobeathigh Zelensdesigncanhaveotherdisadvantages.Ifth

7、etrialrusiveollectionmonitoringthenZelensdesignascontrolpatientswillbeawareofthestudy.tdollectionisnotfeasible,itmaynotsibletouserestrictiveinclusiveorpatientrecruitmentcriteria.Furthermore,ifmanypatientsrefusetheiroriginaltreatment,thisleadtoareductionin er.Boththesefactorswillleadtotheneedforalarg

8、ele 4.SusceptibilityBiases（易感性偏倚different ervention es.Ifdifferentstudygroupshaveprognostic unequallyincrease/decreaseriskto1group,making1groupsceptibleto,and/orundesirableeffectsfromervention,astudysceptibilityInsummary,susceptibilitybiasescanbecreatedbyselectioncriteria,bychanneling,orotherconfoun

9、dingfactorsaswellasbyvariousfeaturesofaninappropriateroup.thesourceofbias,theprognostict e,isidentifiableand abletomeasuredinallgroups,aswithsomeselectioncriteria,itcansometimesbecontrolledforstratificationorysistechniques.Thisismostfeasiblewhenconcurrentgroups compared.Onlyrandomizationcontrolsforu

10、nidentifiableprognostictmight ernalbias.Butrandomizationalonecannotcontrolforallexternaltmayaffect5.otherDetection bias occurs if the methods for e are not uniform either within a ornatestandaTransfer bias occurs when a study feature ervention groups to have unequal follow-easurestheeffectivenessofoneerventionrelativeto anotherby 2009 因任課老師出國(guó)開(kāi)會(huì)原課2009 因任課老師出國(guó)開(kāi)會(huì)原課程安排中 2009-4-1（周三研究方法選擇與病因推斷暫停將與 2009-4- 12009-02-22009-02-32009-02-42009-02-52009-03-62009-03-7