Re: [R] survval analysis microarray expression data

2011-01-10 Thread David Winsemius
On Jan 7, 2011, at 3:33 PM, Terry Therneau wrote: For any given pre-specified gene or short list of genes, yes the Cox model works fine. Two important caveats: 1. Remeber the rule of thumb for a Cox model of 20 events per variable (not n=20). Many microarray studies will have very marginal s

Re: [R] survval analysis microarray expression data

2011-01-10 Thread Unger, Kristian
Dear Terry thank you very much for this. The number of events in my data is well above the suggested size. What concerns me is the fact that a very high proportion of probes comes up as significant when I just randomly select them. This just seems not be biologically meaningful. Do you know of

[R] survval analysis microarray expression data

2011-01-07 Thread Terry Therneau
For any given pre-specified gene or short list of genes, yes the Cox model works fine. Two important caveats: 1. Remeber the rule of thumb for a Cox model of 20 events per variable (not n=20). Many microarray studies will have very marginal sample size. 2. If you are looking at many genes the