应用实例分析临床流行病学研究 胎源性疾病 (dohad)

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Cliquez pour modifier le style du titre,Cliquez pour modifier les styles du texte du masque,Deuxime niveau,Troisime niveau,Quatrime niveau,Cinquime niveau,*,Cliquez pour modifier le style du titre,Cliquez pour modifier les styles du texte du masque,Deuxime niveau,Troisime niveau,Quatrime niveau,Cinquime niveau,*,Cliquez pour modifier le style du titre,Cliquez pour modifier les styles du texte du masque,Deuxime niveau,Troisime niveau,Quatrime niveau,Cinquime niveau,*,应用实例分析,-,临床流行病学研究 胎源性疾病（,DOHAD),学习目标,通过应用实例分析，加深对流行病学重要基本概念的理解,通过应用实例分析，提高对流行病学研究重要方法的应用能力,内容,实例分析 一个经典的有关胎源性疾病的临床流行病学研究报告,实例分析,-,设计一个有关胎源性疾病的临床流行病学研究项目,胎源性疾病,/,发育源性疾病,(DOHAD),The suscepatible ity to many chronic diseases in adulthood can be traced back to exposures during early life(during fetal and early postnatal life),成年期的许多慢性疾病的易感性可以追溯到生命早期的暴露因素（胎儿期和出生后早期）,无致病基因突变,流行病学,-,重要作用之一,发现新联系 （,DOHAD,）,*,Odds ratio for two hour glucose concentration of 7.8 mmol/l adjusted for current body mass index.(X,2,for trend=15.4;p7.8 mmol/l adjusted for current body mass index.,出生体重（,lb),糖耐量异常,n/N,（,%,）,Adjusted,*,OR,Crude,OR,Crude,RR,低于,5.5 lb(2.5kg),8/20(40%),6.6,?,?,5.5-6.4 (2.9 kg),16/47(34%),4.8,?,?,6.5-7.4 (3.4 kg),32/104(31%),4.6,?,?,7.5-8.4 (3.9 kg),26/117(22%),2.6,?,?,8.5-9.4 (4.2 kg),7/54(13%),1.4,?,?,9.5,+lb (4.3 kg+),4/28(14%),1.0,1.0,1.0,Answers to Questions,（,1,）,What is the study design,研究设计是？,Retrospective cohort study,回顾性队列研究,Why OR?why not RR?Either good for reasoning,the latter is more accurate in defining the relative risk disparity.,为什么用比值比（,OR,）？而不是相对风险度（,RR,？推理任一均可，,RR,在定义相对风险差距更准确。,Can we have crude OR and crude RR?Yes,in cohort studies or RCT,you can calculate,RR,.,我们可以计算粗,OR,（未调整比值比）,粗,RR,（未调整相对风险度）吗？是的，在队列研究或试验，可以计算出,RR,。,Why adjusted OR?,Why not a,djusted RR?Either is good for reasoning,it is easier to calculate the adjusted OR.,为什么是调整,OR,？,而不是调整,RR,？推理任一均可，调整,OR,更容易计算,.,For cohort study data,you can use,log binomial model,to obtain the adjusted RR.,队列研究的数据，您可以使用,log,二项式模型，得到调整后的,RR,。,How to calculate adjusted RR,in this study?,在本研究中，如何计算调整后的,RR,？,Answers to Questions,（,2,）,Do we need adjustments in OR or RR?Most times,yes.,我们需要调整吗？大多数时候，是的。,Is adjustments always necessary?No,sometimes unnecessary.,调整是必要的吗？不，有时不必要。,What the difference Between OR and RR?,OR does not always represent RR.OR can be calculated in any study designs,RRs can not be calculated directly in case control studies.OR,和,RR,有什么区别？,OR,有时不能代表,RR,。可以在任何临床流行病学研究设计中计算,OR,。在病例对照研究不能直接计算,RR,。,Whats the difference between,C,rude OR vs.Adjusted OR?,The adjusted OR more often(but not always)represents the true association,。未调整,OR,或与调整,OR,区别是什么？调整,OR,更经常（但并不总是）代表真正的联系。,Whats the difference between Crude RR vs.Adjusted RR?,调整,RR,更经常（但并不总是）代表真正的联系。,真理？假象？,Causal Inference Considerations,因果推理思考,Information bias?,信息偏倚,less likely,Confounding factors,？混杂因素,possibly,Consistency of association?,联系的一致性,yes,Strength of association?,关联强度,OK,Dose-response relationship?,剂量,-,反应关系,yes,Temporally order consistent?,时间一致性,yes,Deterministic/probabilistic?,决定性,no,Necessary?,必要性,no,Sufficient?,充分,no,Specificity?,特异性,no,Biological plausibility?,生物合理性,yes,Surrogate risk factor?,替代风险因素,may be,Animal model experiment?,实验动物模型,yes,Birth weight,出生体重,Crude,O,R,Adjusted,*,O,R,Crude ORs,Is Current BMI a confounder?,*,adjusted for current body mass index,.,Confounder or Effect Mediator?,混杂因素,或影响介质,?,Glucose tolerance,糖耐量,Blood pressure,血压,Current BMI,现体重指数,Birth weight,出生体重,Confounders,混杂因素,(e.g.ethnicity,如种族,),When you inappropriate adjust for a factor in the causal pathway,you could produce a false association,or exaggerated association,当你不适当的调整一个在因果通路途径上的因素，你可能会产生一个虚假的关联，或夸张的关联。,It may be inappropriate to adjust for current BMI in estimating the effect of birth weight on current glucose tolerance or blood pressure.,调整现在的体重指数以估计出生体重对目前的糖耐量或血压的影响可能是不合适的。,Reversal paradox,逆转谜题,Why evidence for the fetal origins of adult disease might be a statistical artifact:the,reversal paradox,for the relation between birth weight and blood pressure in later life.,Tu YK,West R,Ellison GT,Gilthorpe MS.Am J Epidemiol;161(1):27-32.,Some researchers have recently questioned the validity of associations between birth weight and health in later life,.They argue that these associations might be due in part to inappropriate statistical adjustment for variables on the causal pathway(such as current body size),which creates an artifactual statistical effect known as the reversal paradox.,Computer simulations were conducted for three hypothetical relations between birth weight and adult blood pressure.The authors examined the effect of statistically adjusting for different correlations between current weight and birth weight and between current weight and adult blood pressure to assess their impac