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From | Simon <scmoore.lists@googlemail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | st: ssmenu, stcox and sample size estimates |
Date | Wed, 18 Aug 2010 15:33:32 +0100 |
<>I have successfully installed Royston & Babiker's ssmenu (SJ2-2 st0013. A menu-driven facility for complex sample size) and following the help file ran -ssmenu on- to which I received "Study size menu on. The menubar has been changed." However, I cannot see any change in the menu bar. Is this compatible with Stata 11MP? If not, could someone suggest an alternative?
I have data from a pilot RCT, the unit of allocation is premises and each premises is subject to multiple failures. Data is described at the daily level with half of the premises (n=16) receiving the intervention half way through, the other half not. So I have run:
stset date, fail(fail) exit(time .) id(premises) enter(date0)xi: stcox intervention, efron robust schoenfeld(sch*) scaledsch(sca*) cluster(loc)
And from this I would like to estimate the number of premises required in the full study.
Wishing you well Simon * * 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/