实习-答案

实习一疾病频率测量的常用指标五练习题（一）名词解释：答案见课本P16-22（二）单选题1B2B3E4C5B（三）论述题：答案见课本P17-18实习二疾病分布五练习题（一）名词解释：答案见课本P16-22（二）单选题1B2C（三）多选题1ABD2ABD3ABDE4ABCD5BCDE（四）论述题：1.答案见课本P262.答案见课本P33-343.答案见课本P35-364.答案见课本P28实习三现况研究五练习题一单选题1.C2.B3.E4.E5.C6.E7.D8.E二、多选题1.ABCDE2.ABDE3.ABC4.ABCDE5.ABD6.ABCDE三简答题1.现况研究的目的：(1)掌握目标群体中疾病的患病率及其分布状态；（2）提供疾病的致病因素的线索；（3）确定高危人群；（4）对疾病监测、预防接种效果及其他资料质量的评价。现况研究的特点：(1)开始时一般不设对照组；（2）研究某特定时点或时期内某一群体中暴露和疾病的联系；（3）现况研究揭示暴露与疾病之间的统计学联系，仅为建立因果关系提供线索，是分析性研究的基础，不能以此作因果推论；而对不会发生改变的暴露因素，可以作因果推论；（4）用现在的暴露来替代或估计过去情况的条件；（5）现况研究重复进行可以获得发病率资料。2.现况研究常用的抽样方法有：(1)单纯随机抽样；（2）系统抽样；（3）分层抽样；（4）整群抽样；（5）多级抽样。3.决定现况研究的样本大小的因素来自多方面，但主要是：①预期的患病率，如现患率越靠近50％，样本含量就越小；反之，则要大些。②对调查结果精确性的要求，即允许误差越大，则所需样本就越小。四论述题1.现况研究的常见偏倚有（1）选择偏倚：①选择性偏倚；②无应答偏倚；③幸存者偏倚。（2）信息偏倚：①调查对象引起的偏倚；②调查员偏倚；③测量偏倚。防止产生偏倚的措施：（1）正确的研究设计：随即化、标准化方法，研究变量的选择及测量（2）提高研究对象的依从性（3）培训研究人员（4）严格校正仪器（5）严格实验条件及研究方法。2.普查的目的：（1）早期发现病人；（2）了解疾病分布；（3）了解人群健康水平；（4）建立某生理指标的正常值。普查适用于那些有一定患病率，危害严重且有简便易行的诊断手段，而早期发现后能有满意治疗效果的疾病；建立某生理指标正常值需要用普查。普查的优点：（1）确定调查对象上比较简单；（2）可查出某人群中患某病的所有病人，使其得到及时治疗；（3）开展干预如健康教育，了解某病的患病率或健康状况。普查的缺点：（1）普查对象多，调查期限短难免漏查；（2）调查质量不易控制；（3）患病率低、诊断技术复杂的疾病不易进行普查。抽样调查的优点：省时间、省人力、省物力，调查结果准确。抽样调查的缺点：设计、实施及资料分析比普查复杂；重复或遗漏不易被发现；对于变异过大的材料和需要普查普治的情况则不适合用抽样调查；患病率太低的疾病也不适合抽样调查。实习四队列研究(一)名词解释Exposure,Riskfactor，outcomeCohort,Birthcohort,ExposurecohortFixedcohort,DynamiccohortoropencohortCohortstudy/Prospectivestudy/Follow-upstudy/Longitudinalstudy/IncidencestudyProspectivecohortstudyorconcurrentcohortstudy,Historical(Retrospectiveornon-concurrent)CohortStudy,Ambispective(ormixed)cohortstudyPersontimeRisk,Cumulativeincidence,IncidencedensityStandardizedmortalityratio(SMR)Re1ativerisk(RR),riskratio(RR)，rateratio(RR)Attributablerisk(AR),ratedifference(RD),excessriskAttributableriskpercent(AR％)etiologicfraction(EF)Populationattributablerisk(PAR),populationattributableriskpercent(PARP)Losttofollowupbias（二）单选题（选择一个最佳答案）1.Incohortstudiesoftheroleofasuspectedfactorintheetiologyofadisease,itisessentialthat:Da.Therebeequalnumbersofpersonsinbothstudygroupsb.Atthebeginningofthestudy,thosewiththediseaseandthosewithoutthediseasehaveequalrisksofhavingthefactorc.Thestudygroupwiththefactorandthestudygroupwithoutthefactorberepresentativeofthegeneralpopulationd.Theexposedandnonexposedgroupsunderstudybeassimilaraspossiblewithregardtopossibleconfoundingfactorse.Bothbandc2.WhichofthefollowingisNOTanadvantageofaprospectivecohortstudy?Aa.Itusuallycostslessthanacase-controlstudyb.Precisemeasurementofexposureispossiblec.Incidenceratescanbecalculatedd.Recallbiasisminimizedcomparedwithacase-controlstudye.Manydiseaseoutcomescanbestudiedsimultaneously.3.Retrospectivecohortstudiesarecharacterizedbyallofthefollowingexcept:Ca.Thestudygroupsareexposedandnonexposedb.Incidenceratesmaybecomputedc.Therequiredsamplesizeissmallerthanthatneededforaprospectivecohortstudyd.Therequiredsamplesizeissimilartothatneededforaprospectivecohortstudye.Theyareusefulrareexposures4.Amajorproblemresultingfromthelackofrandomizationinacohortstudyis:Aa.Thepossibilitythatafactorledtotheexposure,ratherthantheexposureitself,mighthavecausethediseaseb.Thepossibilitythatagreaterproportionofpeopleinthestudymayhavebeenexposedc.Thepossibilitythatasmallerproportionofpeopleinthestudymayhavebeenexposedd.That,withoutrandomization,thestudymaytakelongertocarryoute.Plannedcrossoverismorelikely.5.Inacohortstudy,theadvantageofstartingbyselectingadefinedpopulationforstudybeforeanyofitmembersbecomeexposed,ratherthatstartingbyselectingexposedandnonexposedindividuals,isthat:Ca.Thestudycanbecompletedmorerapidlyb.Anumberofoutcomescanbestudiedsimultaneouslyc.Anumberofexposurescanbestudiedsimultaneouslyd.Thestudywillcostlesstocarryoute.aandd6.Classifyeachofthestudies(6.1-6.7)describedbelowaseitheraa.Trialb.Cohortstudy,c.Case-controlstudyd.Cross-sectionalstudy,ore.Ecologicalstudy6.1Astudyinvestigatedtherelationbetweenprostatecancerandenergyrestrictionduringchildhoodbyexaminingprostatecanceroccurrencein58,279menaged55-69.Theauthorsfoundnoevidencethatenergyrestrictionearlyinlifedecreasedprostatecancerrisklaterinlife.B6.2Astudycomparedteaconsumptioninheartdiseasepatientsandaseriesofnon-casestodetermineifteaconsumptionswasprotective.C6.3Surgicalpatientswereassignedtooneofthreegroups.Group1receivedantibiotics24hourspriortosurgery,group2receivedantibiotics2hourspriortosurgery,andgroup3receivednoantibiotics.Risksofpost-operativewerecompared.A6.4ResearchersinLiverpool,Englandpublishedalandmarkstudyinwhich66%ofthemotherswhohadgivenbirthtoinfantswithspinalcordmalformationswerefolicaciddeficient.Incontrast,only17%ofthemotherswhohadnormalbabieswerefolicaciddeficient.C6.5TheBritishResearchCouncilcompletedastudyinwhichsomeofthewomeninagroupwhohadgivenbirthtobabieswithneuraltubedefectsinthepastandwhowereonceagainpregnantweresupplementedwithfolicacid.Theinvestigatorsfoundthatsupplementationreducedtheriskofhavingsecondneuraltubedefectbabyby70%.A6.6AttheMayoClinicinRochester,Minnesota,researchersfollowed939patientswhohadbeenclassifiedaseitheroptimistsorpessimists.Afterthirtyyearsofs