On examining non-linearity of Cox coefficients with penalized splines - I
have not been able to dig up a completely clear description of the test
performed in R or S-plus.
One iron clad way to test is to fit a model that has the variable of
interest
x as a linear term, then a second model
On examining non-linearity of Cox coefficients with penalized splines - I
have not been able to dig up a completely clear description of the test
performed in R or S-plus.
From the Therneau and Grambsch book (2000 - page 126) I gather that the test
reported for linear has as its null hypothesis
Use pspline within a Cox model. It includes a fairly general test for
nonlinearity, that is similar to GAM models.
Terry Therneau
coxph(Surv(time, status) ~ ph.ecog + pspline(age), lung)
Call:
coxph(formula = Surv(time, status) ~ ph.ecog + pspline(age),
data = lung)
Hi, I am just wondering if there is a test available for testing if a linear
fit of an independent variable in a Cox regression is enough? Thanks for any
suggestions.
John Zhang
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-Original Message-
From: [EMAIL PROTECTED] on behalf of array chip
Sent: Fri 5/9/2008 2:54 PM
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Subject: [R] how to check linearity in Cox regression
Hi, I am just wondering if there is a test available for testing if a linear
fit of an independent variable
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