生存分析和cox比例风险模型名师优质课赛课一等奖市公开课获奖课件

生存分析

第1页生存分析主要内容生存过程描述生存时间分布特点预计生存率预计平均生存时间绘制生存率曲线生存过程统计推断生存时间影响原因研究第2页生存分析需具备资料生存时间或称时间变量观察结果或称截尾变量暴露变量及混杂原因第3页肾移植例普通手术(A组):391520202630414664+64135223365450596+680+900+900+改进手术(B组):

1070+70+120225366390+475+518+647+801+1001+1045+1045+第4页手术方式生存时间观察结果treattimeoutcome1311911411146116411640………………190002101………………28010210010210450210450第5页生存资料定义(1)将数据定义为生存资料格式stset时间变量[，failure(截尾变量)]failure(截尾变量)stata以全部不等于0非缺失值为预期出现结果；若failure选择项缺省，则stata默认全部纪录均出现结果第6页生存资料定义(2)四个变量---定义数据库后，stata系统自动产生_st /*数据库中该条统计是否被定义为生存资料_d /*该条统计是否出现预期结果_t /*观察对象被随访时间_t0 /*观察对象第一次被观察到时间(开始过程时间为0)第7页stsettime,failure(outcome)

failureevent:outcome!=0&outcome<.obs.timeinterval:(0,time]exitonorbefore:failure------------------------------------------------------------------33totalobs.0exclusions------------------------------------------------------------------33obs.remaining,representing18failuresinsinglerecord/singlefailuredata11370totalanalysistimeatrisk,atriskfromt=0earliestobservedentryt=0lastobservedexitt=1045第8页生存资料描述stci,[by(分组变量)选择项]p(#)/*生存时间百分位数level(#)/*可信区间可信度media/*计算中位生存时间，为默认选项rmean/*计算平均生存时间第9页.stci,by(treat)failure_d:outcomeanalysistime_t:time|no.oftreat|subjects50%Std.Err.[95%Conf.Interval]-------+-------------------------------------------------------------1|196446.8995204502|14..225.-------+-------------------------------------------------------------total|33365143.400164.第10页.stci,rmeanby(treat)failure_d:outcomeanalysistime_t:time|no.ofrestrictedtreat|subjectsmeanStd.Err.[95%Conf.Interval]-------+-------------------------------------------------------------1|19297.0329(*)83.96867132.457461.602|14766.4481(*)116.2397538.622994.274-------+-------------------------------------------------------------total|33512.9716(*)83.84662348.635677.308(*)largestobservedanalysistimeiscensored,meanisunderestimated.第11页生存率预计输出生存率、生存概率标准误等统计量stslist[,by(分组变量)选择项]failure/*输出死亡函数(1-S(t))level /*要求所输出可信区间可信度第12页.stslist,by(treat)failure_d:outcomeanalysistime_t:timeBeg.NetSurvivorStd.TimeTotalFailLostFunctionError[95%Conf.Int.]-------------------------------------------------------------------------------treat=1319100.94740.05120.68120.9924…...6803010.23680.10150.07580.44759002020.23680.10150.07580.4475treat=21014100.92860.06880.59080.98967013020.92860.06880.59080.9896…...10013010.67530.13440.34640.864710452020.67530.13440.34640.8647-------------------------------------------------------------------------------第13页绘制生存（死亡）曲线(1)绘制Kaplan-Meier生存(死亡)曲线stsgraph[,by(分组变量)separate选择项]failure/*指定绘制“死亡”曲线，缺省时绘制生存曲线Gwood/*绘制生存(或死亡)曲线及其Greenwood可信区间lost/*在曲线上标出该时间点截尾值例数第14页第15页绘制生存（死亡）曲线(2)绘制Kaplan-Meier生存曲线与Cox预测曲线stcoxkm[,by(分组变量)separate绘图命令选择项]第16页第17页生存率比较ststest分组变量[,选择项]

logrank/*进行log-rank检验，为缺省值第18页.ststesttreatfailure_d:outcomeanalysistime_t:timeLog-ranktestforequalityofsurvivorfunctions|EventsEventstreat|observedexpected------+-------------------------1|148.572|49.43------+-------------------------Total|1818.00chi2(1)=6.71Pr>chi2=0.0096第19页例8.8某临床试验比较A，B两治疗方案对某病治疗效果，A组(group=0)12人，B组(group=1)13人。病人分组后检验其肾功效(kidney)，功效正常者记为0，不正常者记为1；治疗后生存时间为stime(天)；问不一样治疗方案及肾功效对病人生存时间是否有影响?第20页编号NO.治疗生存观察肾功效kidney编号NO.治疗生存观察肾功效kidney方案时间结果方案时间结果Groupstimecensorgroupstimecensor108111311801020852001416321030521115122400040220101611951050631117176106081018170107019760019113118012960020123119014600021112961010063112212101011013280023170010120365002411811251199000例8.8第21页Cox百分比风险模型(1)预计Cox百分比风险模型命令格式为stcox[协变量][,nohr选择项]nohr/*指定输出回归系数b而不是危险比exp(b)level(#)/*可信区间可信度第22页例8.8Stsetstime,failure(censor)Stcoxgroupkidney,nolognohrfailure_d:censoranalysistime_t:stimeCoxregression--Breslowmethodforties

No.ofsubjects=25Numberofobs=25No.offailures=17Timeatrisk=15334LRchi2(2)=22.67Loglikelihood=-35.707534Prob>chi2=0.0000------------------------------------------------------------------------------_t|_d|Coef.Std.Err.zP>|z|[95%Conf.Interval]-------------+----------------------------------------------------------------group|1.243078.59931772.070.038