I am running mixed effect Cox models (I have 1 random effect factor) using the coxme
function {coxme
} in R, and I would like to check the assumption of proportional hazard.
I know that the proportional hazards (PH) assumption can be verified with the cox.zph
function {survival
} on cox.ph
model.
However, I cannot find the equivalent for coxme
models.
In 2015 a similar question has been posted here, but had no answer.
My questions are:
- How to test PH assumption on mixed effect cox model
coxme
? - If there is no equivalent of the
cox.zph
forcoxme
models, is it valid for publication in scientific article to run mixed effectcoxme
model but test the PH assumption on acox.ph
model identical to thecoxme
model but without random effect?
Best Answer
Apologies for making this a separate answer, but I cannot comment because I have less than 50 reputation.
Oka suggested using frailty in connection with
coxph
in order to test the proportional hazard assumption. I believe it is worth noting that the documentation for frailty mentions, "thecoxme
package has superseded this [frailty
] method." For this reason, the original question about "how to test the PH assumption on mixed effect cox modelcoxme
," has strong justification to stay within the scope ofcoxme
.