生存分析和cox比例風(fēng)險模型名師優(yōu)質(zhì)課賽課一等獎市公開課獲獎?wù)n件

生存分析

第1頁生存分析主要內(nèi)容生存過程描述生存時間分布特點(diǎn)預(yù)計生存率預(yù)計平均生存時間繪制生存率曲線生存過程統(tǒng)計推斷生存時間影響原因研究第2頁生存分析需具備資料生存時間或稱時間變量觀察結(jié)果或稱截尾變量暴露變量及混雜原因第3頁腎移植例普通手術(shù)(A組):391520202630414664+64135223365450596+680+900+900+改進(jìn)手術(shù)(B組):

1070+70+120225366390+475+518+647+801+1001+1045+1045+第4頁手術(shù)方式生存時間觀察結(jié)果treattimeoutcome1311911411146116411640………………190002101………………28010210010210450210450第5頁生存資料定義(1)將數(shù)據(jù)定義為生存資料格式stset時間變量[，failure(截尾變量)]failure(截尾變量)stata以全部不等于0非缺失值為預(yù)期出現(xiàn)結(jié)果；若failure選擇項(xiàng)缺省，則stata默認(rèn)全部紀(jì)錄均出現(xiàn)結(jié)果第6頁生存資料定義(2)四個變量---定義數(shù)據(jù)庫后，stata系統(tǒng)自動產(chǎn)生_st /*數(shù)據(jù)庫中該條統(tǒng)計是否被定義為生存資料_d /*該條統(tǒng)計是否出現(xiàn)預(yù)期結(jié)果_t /*觀察對象被隨訪時間_t0 /*觀察對象第一次被觀察到時間(開始過程時間為0)第7頁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頁生存資料描述stci,[by(分組變量)選擇項(xiàng)]p(#)/*生存時間百分位數(shù)level(#)/*可信區(qū)間可信度media/*計算中位生存時間，為默認(rèn)選項(xiàng)rmean/*計算平均生存時間第9頁.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頁.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頁生存率預(yù)計輸出生存率、生存概率標(biāo)準(zhǔn)誤等統(tǒng)計量stslist[,by(分組變量)選擇項(xiàng)]failure/*輸出死亡函數(shù)(1-S(t))level /*要求所輸出可信區(qū)間可信度第12頁.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頁繪制生存（死亡）曲線(1)繪制Kaplan-Meier生存(死亡)曲線stsgraph[,by(分組變量)separate選擇項(xiàng)]failure/*指定繪制“死亡”曲線，缺省時繪制生存曲線Gwood/*繪制生存(或死亡)曲線及其Greenwood可信區(qū)間lost/*在曲線上標(biāo)出該時間點(diǎn)截尾值例數(shù)第14頁第15頁繪制生存（死亡）曲線(2)繪制Kaplan-Meier生存曲線與Cox預(yù)測曲線stcoxkm[,by(分組變量)separate繪圖命令選擇項(xiàng)]第16頁第17頁生存率比較ststest分組變量[,選擇項(xiàng)]

logrank/*進(jìn)行l(wèi)og-rank檢驗(yàn)，為缺省值第18頁.ststesttreatfailure_d:outcomeanalysistime_t:timeLog-ranktestforequalityofsurvivorfunctions|EventsEventstreat|observedexpected------+-------------------------1|148.572|49.43------+-------------------------Total|1818.00chi2(1)=6.71Pr>chi2=0.0096第19頁例8.8某臨床試驗(yàn)比較A，B兩治療方案對某病治療效果，A組(group=0)12人，B組(group=1)13人。病人分組后檢驗(yàn)其腎功效(kidney)，功效正常者記為0，不正常者記為1；治療后生存時間為stime(天)；問不一樣治療方案及腎功效對病人生存時間是否有影響?第20頁編號NO.治療生存觀察腎功效kidney編號NO.治療生存觀察腎功效kidney方案時間結(jié)果方案時間結(jié)果Groupstimecensorgroupstimecensor108111311801020852001416321030521115122400040220101611951050631117176106081018170107019760019113118012960020123119014600021112961010063112212101011013280023170010120365002411811251199000例8.8第21頁Cox百分比風(fēng)險模型(1)預(yù)計Cox百分比風(fēng)險模型命令格式為stcox[協(xié)變量][,nohr選擇項(xiàng)]nohr/*指定輸出回歸系數(shù)b而不是危險比exp(b)level(#)/*可信區(qū)間可信度第22頁例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