Re: multivariate Cox model p values

sorry, what I meant was: I can imagine that a variable may appear
significant in unvariable analysis and the significance disappeared in
multivariable analysis because the effect can be taken away by other
correlated variables
arrayprofile@xxxxxxxxx wrote:
Hi, I encountered a situation when I ran Cox proportional regression
with 6 independent variables. If I ran the regression with each
independent variable separately (i.e. univariable analysis), only 1
variable is significant. when I ran the Cox regression with all
variables together in one model (i.e. multivariable analysis), not only
the variable significant in the univariable analysis is still
significant, but 2 of the other variables showed significant as well.
How to explain this?

I can imagine that a variable may appear insignificant in unvariable
analysis and disappeared in multivariable analysis because the effect
can be taken away by other correlated variables, but can't think of a
reason why the opposite can happen. Can anybody explain?

Thanks

John

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