考克斯危害模型和趋势测试

Question

如果我有一个Cox比例风险模型，并使用一个分类变量（以及其他协变量，例如年龄等）作为事件的预测因子，那么例如，我感兴趣的分类变量是肿瘤大小，可以是0-10、10-例如20、20-30，我发现随着肿瘤大小的增加，死亡心率有增加的趋势，我该如何在r中计算并获得ap？

Answer 1

There is a bit of danger in accepting your incomplete specification since you could have a size classification that will mess this up, as for example: 0-10, 10-20, 20-30, 30-80, 80-120, 120-240. Unless you have carefully constructed your factor to have correctly ordered ascending levels, what I am about to suggest as a shortcut will fail.

 survmdl <- coxph(Surv(tie,event) ~ as.numeric(fact), data=dat)

You will get a "test of trend" which would be interpreted as the per-category increase in the log(Hazard) for rising size and it would be a single coefficient. So post your actual factor levels if you wnat a better considered reply.