search for: xzbeta1

Displaying 2 results from an estimated 2 matches for "xzbeta1".

2011 Nov 14
0
Enquiry about 2nd-order interactions survival analysis
David's answers were correct. You are looking deep into the code when there is no reason to to so. 1. h(t|(X=x,Z=z)) = exp(Beta0 + XZBeta1) Most statisticians will tell you that this is an unwise model. The reason is that if you replace X with "X+1" the fit changes, which is almost never desirable. What if someone coded your dummy variable as 1/0 instead of 0/1 -- wouldn't you want to get the same fit Therefore the...
2011 Nov 12
2
Second-order effect in Parametric Survival Analysis
Hi experts, http://r.789695.n4.nabble.com/file/n4034318/Parametric_survival_analysis_2nd-order_efffect.JPG Parametric_survival_analysis_2nd-order_efffect.JPG As we know a normal survival regression is the equation (1) Well, I'ld like to modify it to be 2nd-order interaction model as shown in equation(2) Question: Assume a and z is two covariates. x = dummy variable (1 or 0) z = factors