Many thanks! 2011/3/18 Marc Schwartz <marc_schwa...@me.com>
> On Mar 18, 2011, at 6:06 AM, Dunia Scheid wrote: > > > Hello, > > > > I am trying to compute the mdeian of the survival time from the function > > survfit: > > > >> fit <- survfit(Surv(time, status) ~ 1) > >> fit > > Call: survfit(formula = Surv(time, status) ~ 1) > > > > records n.max n.start events median 0.95LCL 0.95UCL > > 111 111 111 20 NA NA NA > > > > The results is NA? the fit$surv gives values between 1 and 0.749! Am I > doing > > this correct? Is there a correct way to do this? > > > > Many thanks for your help, > > Dunia > > > Median survival is the time at which the survivorship function equals 0.5. > Since your minimum value appears to be 0.749, you never get there, thus the > output shows NA. > > If you did not have any censored observations, median survival would also > be the point at which 50% of your sample has not yet observed the event of > interest. > > See ?print.survfit for additional information specific to this function. > > HTH, > > Marc Schwartz > > [[alternative HTML version deleted]] ______________________________________________ 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.