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From | "Lambert, Paul C. (Dr.)" <pl4@leicester.ac.uk> |
To | "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |
Subject | st: RE: Using the knotstvc option within stpm2 |
Date | Sun, 9 Sep 2012 23:48:55 +0100 |
Alison, This is a bug that I think was introduced in the last update. I will fix this for the next update, which I am currently working on. In the meantime I will send you a working version privately. Paul Dr Paul C Lambert Reader in Medical Statistics Centre for Biostatistics & Genetic Epidemiology Department of Health Sciences University of Leicester 2nd Floor, Adrian Building University Road Leicester LE1 7RH Tel: +44 (0)116 229 7265, Fax: +44 (0)116 229 7250 e-mail: paul.lambert@le.ac.uk Homepage: http://www2.le.ac.uk/Members/pl4/ ________________________________________ From: owner-statalist@hsphsun2.harvard.edu [owner-statalist@hsphsun2.harvard.edu] On Behalf Of Turnbull, Alison E. [aturnbul@jhsph.edu] Sent: Sunday, September 09, 2012 9:30 PM To: statalist@hsphsun2.harvard.edu Subject: st: Using the knotstvc option within stpm2 Hello, I've been using stpm2 to fit a flexible parametric survival model. Everything worked quite smoothly until I tried to specific the location of knots for time-dependent effects. According to the instructions: "knotstvc(knotslist) defines numlist knotslist as the location of the interior knots for time-dependent effects. If different knots are required for different time-dependent effects the option is specified, for example, as follows: knotstvc(x1 1 2 3 x2 1.5 3.5)" I've successfully run models with knots in the baseline distribution function at time = 3, 7, and 21. Adding cumfail_10 and sx_trauma as time-dependent effects substantially improves the fit of the model. I'd like to specify that cumfail_10 should have an interior knot at time = 21 and sx_trauma should have an interior knot at time = 24. However when I run the following model: stpm2 x1 x2 x3 x4 x5 x6 x7 cumfail_10 sx_trauma, scale(hazard) knots(3 7 21) tvc(cumfail_10 sx_trauma) knotstvc(cumfail_10 21 sx_trauma 24) eform I get the following warning: "You must give tvc variable names when using knotstvc() option." Can anyone see what I'm doing wrong? Thanks, alison * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/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/statalist/faq * http://www.ats.ucla.edu/stat/stata/