Re: [問題] 有關存活分析的問題
※ 引述《hospice (平安快樂)》之銘言:
: 您好:
: 再次感謝您的回覆!
: 不過在下資質駑鈍,
: 有些地方還是不明白。
: Is the prognostic factor an event time? If not, why do you even
: consider survival analysis.
: 您這裡的意思是說預後因子是否為 event time嗎?
: 對不起我是新手不太清楚您的意思,
: 我看的paper都是將年齡分成兩組(>60 or <60),
: 腫瘤大小分為兩組(<3cm or <3cm)等等,
: 來看Disease-specific survial(DSS)或Recurrent-free survival(RFS),
: 用的是Kapaln-Meiner Method
: 因此我們才想如法炮製,
: 將tumor recurrence與否分成兩組(yes or no),
: 來看Disease-specific survial(DSS)或Recurrent-free survival(RFS)
Okay. Then the endpoint is time to a specific event, subject to censoring.
You should use methods for survival data.
: Are you planing to treat tumor recurrence as a binary variable?
: If yes, you better define a time frame. Otherwise, you may consider
: treating it as a time-dependent covariate.
: 沒錯,我們正是想把tumor recurrence當成binary variable,
: 只是不知道這樣做合不合理?因為沒有paper有這樣做過,
: 您說的time frame是怎麼一回事?有沒有相關的參考資料呢?
Based on the description, it is better to treat "tumor recurrence" as
a time-dependent covariate. Keep in mind that the status of tumor
recurrence for those who loss to follow-up may be unknown.
: Do you mean to estimate the K-M curve for those with and without cancer
: recurrence separately?
: 是的,如同上面所說的,
: 我們是想這樣做!不知道行不行的通?
Again, how would you define the value of the "tumor recurence" variable for those
who loss to follow-up and do not have tumor recurrence before they drop out?
: 如果用t test 來看兩組存活天數的話,
: 可以得到無 recurrence的mean±SD,以及有recurrence的mean±SD,以及p值,
: 不過這好像不是正確的作法,而且存活天數有極端值,有的只追蹤一兩週就loss follow up,
: 有的可以追蹤到好幾年!
The t test is not appropriate for survival data.
※ 編輯: bmka 來自: 71.255.237.189 (07/11 12:17)
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