Ravi's last note finished with > I am wondering why Terry Therneau's "survival" package doesn't > have this option.
The short answer is that there are only so many hours in a day. I've recently moved the code base from an internal Mayo repository to R-forge, one long term goal with this is to broaden the developer base to n>2 (me and Thomas Lumley). A longer statistical answer: I'm not sure if the "this" of Ravi's question is a. smoothed hazards, b. the K&P cumulative incidence or c. the Fine & Gray model. b. I like the CI model and am using it more. We also have local code. The latest version of survival (on rforge, likely in the next default R release) has added simple CI curves to the survfit function. Adding code for survfit on Cox models is on the todo list. But -- this release also fixes up survfit.coxph to handle weighted Cox models and that was on my list for approx 10 years, i.e., don't hold your breath. I don't release something until it also has a set of worked out test cases to add to the 'tests' directory. a. smoothed hazards. For the case at hand I don't see any particular advantage of this. On the other hand, I often would like to display hazard functions instead of CI functions for Cox models; with time dependent covariates I don't think a survival curve makes sense. But I haven't had the time to think through exactly which methods should be added. c. Fine & Gray model, i.e., where covariates have a direct influence on the competing risk. I find the model completely untenable from a biologic point of view, so have no interest in adding it. (Due to finite time, everything in the survival package is code that I needed for an analysis; medical research is what pays my salary.) Assume that I have competing processes/risks, say progression of a tumor and heart disease; I expect that the tumor process pays no attention whatsoever to what is going on in the heart. But this is necessary if "type=squamous" is modeled as an absolute beta=__ increase in the CI for cancer. The squamous cells need to "step up the pace" of invasion if heart failure threatens, like jockeys in a horse race. Terry T. ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
