One possibility is to use the -powercal- package, downloadable from SSC. In Stata, use the commands
ssc describe powercal
ssc install powercal, replace
to do this.
More about the use of -powercal- (including an application to logistic regression) can be found in the -powercal- manual (distributed with the -powercal-
package as an ancillary file), or in Newson (2004).
I hope this helps.
Best wishes
Roger
References
Newson R. Generalized power calculations for generalized linear models and more. The Stata Journal 2004; 4(4): 379-401. Download pre-publication draft from
http://www.imperial.ac.uk/nhli/r.newson/papers.htm
Roger Newson
Lecturer in Medical Statistics
Respiratory Epidemiology and Public Health Group
National Heart and Lung Institute
Imperial College London
Royal Brompton campus
Room 33, Emmanuel Kaye Building
1B Manresa Road
London SW3 6LR
UNITED KINGDOM
Tel: +44 (0)20 7352 8121 ext 3381
Fax: +44 (0)20 7351 8322
Email: [email protected]
Web page: www.imperial.ac.uk/nhli/r.newson/
Departmental Web page:
http://www1.imperial.ac.uk/medicine/about/divisions/nhli/respiration/popgenetics/reph/
Opinions expressed are those of the author, not of the institution.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Nico Hutter
Sent: 15 August 2007 13:49
To: [email protected]
Subject: st: Power calculation for Beta/Odds Ratios in logistic regression models
Hi everyone,
we would like to run a power calculation for beta-coefficients / odds
ratios in logistic regression models with covariates.
Is such a procedure implemented in SATA?
Used command for the logistic regression model:
svy: logit depression age sex comorbidity, or
Data stems from a national representative survey. Dependent variable is
depression. Comorbidity is dichotomised. Now, we are interested in the
"post hoc" power of the odds ratio of comorbidity.
Can anybody give us some advice, please? Thanks in advance!
--
Nico Hutter, Dipl. Psych.
Abt. f�r Rehabilitationspsychologie und Psychotherapie
Institut f�r Psychologie
Universit�t Freiburg
D-79085 Freiburg
Tel: +49(0)761/203-9172
Fax: +49(0)761/203-3040
http://www.psychologie.uni-freiburg.de/Members/hutter
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