r - 如何获得survdiff返回的p值

Question

我正在使用 R 生存包，survdiff 函数。我想知道如何从返回值中获取 p 值。

> diff = survdiff(Surv(Time, Censored) ~ Treatment+Gender, data = dat)
> diff
Call:
survdiff(formula = Surv(Time, Censored) ~ Treatment + Gender, 
    data = dat)

                            N Observed Expected (O-E)^2/E (O-E)^2/V
Treatment=Control, Gender=M 2        1     1.65  0.255876  0.360905
Treatment=Control, Gender=F 7        3     2.72  0.027970  0.046119
Treatment=IND, Gender=M     5        2     2.03  0.000365  0.000519
Treatment=IND, Gender=F     6        2     1.60  0.100494  0.139041

 Chisq= 0.5  on 3 degrees of freedom, p= 0.924 

我想使用一些函数获得 p 值 0.924。谢谢。

Answer 1

p 值未存储在 survdiff 类中，因此必须在输出时即时计算。要重现 p 值，可以使用 chisq 分布函数:“pchisq”

diff = survdiff(Surv(Time, Censored) ~ Treatment+Gender, data = dat)
pchisq(diff$chisq, length(diff$n)-1, lower.tail = FALSE)