-----Original Message-----

I have a dataset which for the sake of simplicity has two endpoints. We would like to test if two different end-points have the same eventual meaning. To try and take an example that people might understand better:

Lets assume we had a group of subjects who all received a treatment. The could stop treatment for any reason (side effects, treatment stops working etc). Getting that data is very easy. Measuring if treatment stops working is very hard to capture... so we would like to test if duration on treatment (easy) is the same as time to treatment failure (hard).

--- End ----

The problem you describe is known as "surrogate endpoints" and addressing it is harder than you think. You will need to look in the literature to gain an understanding of the issues before you proceed. Your question is an important one and lots of folks have thought about it more deeply than I.

Cohn JN (2004). "Introduction to Surrogate Markers". Circulation (American Heart Association) 109 (25 Suppl 1): IV20–1. doi:10.1161/01.CIR.0000133441.05780.1d

Fleming T, David D. Surrogate End Points in Clinical Trials: Are We Being Misled? Ann Intern Med. 1996 Oct 1;125(7):605-13

Terry T.

______________________________________________
R-help@r-project.org 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.
  • [R] Comp... Polwart Calum (COUNTY DURHAM AND DARLINGTON NHS FOUNDATION TRUST)
    • Re:... Andrews, Chris
    • Re:... Polwart Calum (COUNTY DURHAM AND DARLINGTON NHS FOUNDATION TRUST)
    • Re:... Terry Therneau

Reply via email to