Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: Survival analysis - comparing a subset of the sample to the entiresample


From   Richard Aplenc <raplenc@cceb.med.upenn.edu>
To   statalist@hsphsun2.harvard.edu
Subject   st: Survival analysis - comparing a subset of the sample to the entiresample
Date   Thu, 04 Sep 2003 06:53:41 -0400

Hi,

I have a dataset with 1200 patients and time to event (relapse and
death). Of these patients, 500 have data on a particular genotype, of which the variant allele is associated with an increased relapse risk.

I would like to compare the relapse free survival estimate (RFS) of the
overall study group to the RFS estimate of the patients with genotypes. That is, I want to show that the patients with genotype information (both wildtype and variant genotypes combined) do not overall have a significantly different risk of relapse than all patients on the trial.

Thus, I have 2 questions:

1. How do I do this in STATA?

2. Are there issues of lack of independance in the data that make this comparison problematic from a statistical standpoint?

Thank you very much in advance.

Richard
--
Richard Aplenc, MD, MSCE
Pediatric Oncology/Stem Cell Transplant
Children's Hospital of Philadelphia
Center for Clinical Epidemiology and Biostatistics
University of Pennsylvania
215-573-0259 (lab)
215-590-4183 (fax)
raplenc@cceb.med.upenn.edu

*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/




© Copyright 1996–2021 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index