Message-ID: <CALOgBOJiXhk=SSx6kE=LxtJXLCyVov7QSPZRTwoeF9Z8-EMP9g@mail.gmail.com>
Date: 2012-02-20T02:05:45Z
From: Paul Johnston
Subject: Reporting Kaplan-Meier / Cox-Proportional Hazard Standard Error, km.coxph.plot, survfit.object
What is the best way to report the standard error when publishing
Kaplan-Meier plots? In my field (Vascular Surgery), practitioners
loosely refer to the "10% error" cutoff as the point at which to stop
drawing the KM curve. I am interpreting this as the *standard error
of the cumulative hazard*, although I'm having a difficult time
finding some guidelines about this (perhaps I am not searching the
correct terms or references). My KM figures contain typically two
curves that I am comparing using the logrank test. Inspecting the
?survfit.object yields the std.err field that gives the standard error
for each timepoint on the curve.
Is it recommended that I just name the timepoint at which the standard
error exceeds 0.1 in the figure legend? For example, "The standard
error exceeds 10% at time points beyond 394 days." I have seen this
strategy in other publications.
What is your approach?
Thanks for your help,
PCJ