- Thread starter Logician
- Start date
- Tags variables in models

If you are reviewing a Cox regression within a paper, the authors should state their inclusion/exclusion criteria. I typically use a predefined level of significance (e.g., 0.05) and also add a line about clinical significance (in order to control for specific variables of interest). It all depends on their goals.

Well if a sample is small enough it may not be reflective of the population under investigation and you might get near complete seperation (all people with an event are male when this may be an artifact).

What is the sample, how many events, and how many covariates including dummies?

What is the sample, how many events, and how many covariates including dummies?

Roughly how many covariates could I use without the model become unstable? i know it depends on many things , but can we put a range, roughly.

That is for logistic, I would assume some similar rules may be postulated for Cox, but I don't know them off hand. You may get just a little more wriggle room since you have time to event, but not much. If you find some general rules, I would be interested in hearing about them.