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From | <A.J.M.de_Craen@lumc.nl> |
To | <statalist@hsphsun2.harvard.edu> |
Subject | RE: st: Is there a similar command as roccomp for comparing two kaplan-meier curves? |
Date | Mon, 8 Oct 2012 07:59:59 +0000 |
Thank you Steve, I was indeed not completely clear. Let me retry. For 600 individuals I have calculated two measures of kidney function based on different blood parameters. First, I select those with a poor kidney function based on one variable, and run a survival analysis. Then I select those with a poor kidney function on the other variable, and run a survival analysis again. Obviously, there are many individuals in both analyses, but some only have a poor kidney function on one variable, and others only on the other. When I look at the two Kaplan-Meier curves in one graph, I see a clear difference between the two lines. How do I test whether they are statistically significant from each other? Regards, Ton -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Steve Samuels Sent: maandag 8 oktober 2012 4:02 To: statalist@hsphsun2.harvard.edu Subject: Re: st: Is there a similar command as roccomp for comparing two kaplan-meier curves? Your question is not clear. There cannot be two KM curves that both are based on the same individuals, as the KM curve is unique, given the sample. As asked in the FAQ Section 3.3, please show us the Stata commands that produce the KM curves that you wish to compare. If you can, illustrate the problem in one the data sets referenced in the -help- for the command. Steve On Oct 7, 2012, at 3:32 PM, <A.J.M.de_Craen@lumc.nl> <A.J.M.de_Craen@lumc.nl> wrote: Is there a similar command as roccomp for comparing two kaplan-meier curves? I want to compare the predictive value of two different variables in the same dataset. Note that the all individuals are in both K-M curves. Thanks, Ton de Craen * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/