医学统计学-研统一振球湘雅医学院

Postgraduatebooks mendedbyDegreeManagementandPostgraduateEducationBureau,MinistryofEducation1《医《医学统计学》2002年第一，2010年第三版，主编振球（中南大学湘雅医学院生活中的统计问题药物疗效的判断？(假设检验的几率？(概率论身高与父母身高的关系？(相关与回归同龄孩子为什么有胖有瘦(医学参考值人口普查资料(抽样统计学是对令人困惑费解的数字问题做出设想的艺术医 中的统计学问NewScience杂74%17%拼凑实验结7%凭空捏造数 Ⅳ2%故意曲解结今日科学2015-10-重庆 学副校 Statistics----Asciencedealingwiththecollection,ysis,interpretation,andpresentationofmassesofnumericaldata”(Webster,sinternationalThescienceandartofdealingwithvariationindatathroughcollection,classificationand ysisinsuchawayastoobtainreliableresults.(ADictionaryof什么是医学统计Definition：thesciencethatstudycollection,sorting ysisofmedical第一节统计学的几个基本概homogeneityandparameterandpopulationandVariableandrelativefrequentyand8同质与变异

characteristicsforthegivenvariation:differenceexistingamongthevariablevaluesofhomogeneityindividuals参数与统计量（parameterand表示。如μ。表示。如μ。量总体与样(populationanddeterminedbyspecificFinitepopulation：thespace,timepopulationforaspecificpopulationbeenInfinitepopulation：notimeandspacelimitsforthepopulation.Suchpopulationsonlyexistinimagination,soitiscalledinfinitepopulation3.总体与样本(populationandSampling

Thesetofvariablevaluesofsomeindividualssampledfromthepopulationatrandom.减少抽样误差方（1）改进抽样方法（误差从大到小整群抽样单纯随机抽样系统抽样分层抽增加样本选择变异程度较小的研究指标抽样方1234512345抽抽抽抽抽Simplerandom

SimplestandbasicToselectnumbernsubjectsbydrawinglotorbyusingatableofrandomnumberfrompopulationwithNunitsEqualchanceforeachsubjectin

Rankeveryunitsbyacharacterconstructand

numberDefinethesizeofthesampleandcalculatesampling (k=N/n)Drawarandomnumber(k)forstartingDraweverykunitsfromfirstunitExample:Systematic整群抽 Cluster单纯整群抽样（SimpleclusterTheentirepopulationofinterestisdividedintogroups,orclusters,andarandomsampleoftheseclustersisselected.Theentirepopulationofinterestisdividedintogroups,orclusters,andarandomsampleoftheseclustersisselected.Example:ClusterSectionSectionSectionSectionSectionSection StratifiedFirst,stratifythepopulationintoseveralstratabycharacterofareasages,etc.thenselectobjectsusingrandomsamplingineach分层随机分组(stratified总体

可按、性育水多级抽 Multistage在大型流行病学中常用。Multi-stageMulti-stagesamplingisakindofcomplexsampledesigninwhichtwoormorelevelsofunitsareimbeddedoneintheother.进4.变量与资料（variableandMeasurementdata:itMeasurementdata:italsocalledornumericaldata.ItsMeasurementdatahasmeasurement计数资料（enumeration

Enumerationdata:qualitativeorcountdata.Forsuchdata,itneedstoclassifytheobservationunitsbeforeandcountthem.Binomial:gender,liveordeath,yesorMultiplebloodtype,A、B、O、5040302010博士等级资料等级资料ranked等级等级资（半定量资料、料将观察单位按着某种属性不Rankeddata:ordinalortativedata.Itneedtoclassifyobservatoryunitsintodifferentclassesaccordingtheextentbeforecalculatethefrequenciesofeachgroups.Thereexistsobviousdifferencesamongdifferentclasses.特半定量性质，每一个观察单位没有确切值各组之间有性质上的差别或程度上☆各类资料可以转化，由高级向低级资料分病例(岁身血心电尿职1女A正—教2男B正—工3男O正＋职4女正＋农5男A异工6女B正工7女O异8男正9女O正＋变量转原则：变量只能由高级向低级转连续有多连续有多分二分离散型变量常常通过适当的变换或连续性校正后借用连续型变量或有序变量的方法来分析。5.误差误差：泛指实测值与真值之差Error：thedifferencebetweenmeasurementvalueandtrue分类；随机误差(random非随机误差(nonrandom系统误差(systematic 问题：哪类误差用统计学方法可以控制？为什么随机误差（Randomunstableandchangingatrandomerrorsthatcausedbyuncontrolledfactors.Commonly,randerrorsarereferredtothoseerrorsappearingduringrepeatedmeasurementsand

非随机误差(nonrandom系统误差：实验过程中产生的误差，它的值或恒定不变，或遵循一定的变化规律，其产生的原因往往是可知的或可能掌握的。Systematicerror:itisproducedinexperimentandkeepsconstantorchangesaccordingcertainrules.Usually,itsreasonsareknownandcontrollable.

非系统误差（过差）然而造成的误差。Nonsystematicerror）:itisalwayscausedbyobviousgrosses.6、频率与概率（frequencyandprobability:thelikelihoodrandomprobability:thelikelihoodrandomfrequency：Giventhesamecondition,repeatatrialforntimesindependently.Amongntrials,Aappearsformtimes，sotheratioofm/niscalledthefrequencyofrandomeventAamongntrials.频率与概率关必然事件P1不可能事件P=0随机事件P0.05或P0.01称为小概率事件，统计第二节医学统计工作的基本步

of

(sorting

ysisSection thestepsforstatistical一、设计设设实验设 设统计设专业设统计设专业设专业设实实验设计的基本医学设计基本原Principlesofresearch对照的形随机化随机化的作随机的方重复的情盲均衡盲 有效率80%，平均疗效三周。你认同此说法？ 间为3-5月间，结果认为第二组疗效显著高于第一随机化原则随机抽样 有相同的机会被抽随机分组 先后接受处理的机会相简单随机分组示

AB重复(repeated)原①整个实验的重复②多个受试对象重复(samplesize)③同一受试对象重均衡（balance)原单盲(singleblindmethod)双盲(doubleblindmethod)三盲(tripleblindmethod)单 (single (double三盲(triple二、 料(collectionof工作记专 或实验研统计年鉴和统计数据专

statisticalreportingroutinerecordspurposivesurveysorstatisticalyearbookan