Sample Size for an Unmatched Case-Control StudyKevin M. SullivanMHA: cdckms@sph.emory.edu
case-control-study Case-ControlStudy （病例对照研究）1.BasicConcepts Astudystartswiththeidentificationofpersonswiththediseaseofinterestandacontrolgroupofpersonswithoutthedisease,tomeasuretheassociationbetweentheexposureandthediseasebycomparingthediseasedandnon-diseasedwithregardedtohowfrequentlytheexposurepresent.Exposure ...
第五章 病例对照研究 (case-control study);病例对照研究设计应用史;第一节 基本原理;病例对照研究(case control study):以一组患有某病者(病例)和一组或几组未患该病但在某些已知因素方面与病例组相似者(对照)为研究对象,调查他们过去是否暴露于某个或某些可疑致病因素或暴露剂量,比较两组暴露比值,推断研究因子...
病例对照研究 (Case-Control Study) ? 内容 概述 设计和实施 资料的整理和分析 优点和局限性 概 述 ?一、病例对照研究的定义 选择患有某特定疾病的病人作为病例,以不患有该病但具有可比性的个体作为对照,调查他们发病前对某个(些)因素的暴露情况,比较两组中暴露率和暴露水平的差异,研究该疾病与这个(些)因素...
第五章病例对照研究case-controlstudy 第五章病例对照研究（case-controlstudy）1.基本原理2.研究类型3.研究实例4.研究设计与实施5.资料的整理与分析6.常见偏倚及其控制7.实施病例对照研究应注意的问题8.与队列研究优缺点的比较 病例对照研究设计应用史 1843年Guy：职业暴露与肺结核的关系（...
Calculates Sample Size or Power for Matched Case-Control Studies (Stata)Description sampsimcc calculates the power and sample size for a matched case control study. The theory behind this command is described in Dupont (1988) Power Calculations for Matched Case-Control Studies, Biometrics.Mander...
5. Sample Size • Parameters The proportion of exposure that study factors in control group(P 0 ) Odds ratio ( OR) by study factors αvalue 1-β •Methods Table method Formula method (unmatched) p 1 =p 0 RR/[1+p 0 (RR-1)] =(p 0 + p 1 )/2 = l- p q p q p exampl...
CASE-CONTROLSTUDIES 这是神马研究？Cross-sectionalstudy Criticaldesignissue:Directionality Directionalitydefineswhenexposurevariableisobservedrelativeintimetowhenthehealthoutcomeisobserved Time BackwarddirectionalstudyDisease Comparespreviousexposuresinpersonswithandwithoutthedisease ExposureCase-controlstudies Commontypesof...
The purpose of this study is to see if genetic variants in the MTHFR gene are associated with a higher risk of ischemic stroke among the Egyptian population. A case–control study was conducted at Mansoura University Hospital, involving 100 stroke patients and 150 healthy volunteers as the ...
UNEXP EXP Otherwise, sample is biased, OR is also biased In a cohort study: I0=A0/T0 I1=A1/T1 In a case-control study: Case=A0+A1 Control=K0*T0+K1*T1 If cases are from a population cohort The controls must be selected in such a way that the relative sizes of the denominators ...