[R] bias sampling

[David Winsemius]

On Mar 16, 2012, at 1:09 PM, niloo javan wrote:

> hi
> i want to analyze Right Censore-Length bias data under cox model  
> with covariate.
> what is the package ?

I initially left this question alone because I thought there might be  
viewers for whom it all made perfect sense. After two days that  
probability seems to be declining. The problem I had was the meaning  
of "length bias data". Are you talking about a non-proportional effect  
in which the assumption of a constant hazard ratio over time is false  
and other methods are needed. If that is correct, then you should get  
a copy of Therneau and Grambsch's "Modeling Survival Data" and study  
the chapter on "Functional Form'. The package would be "survival".

-- 
David Winsemius, MD
West Hartford, CT