On Nov 19, 2012, at 1:57 AM, wouterjohannes wrote:
No, I never got any response. I used an article by Knol to solve the
issue. Ik hope this is useful for you too.
Best regards,
Wouter
Knol, M.J., van, d.T., Grobbee, D.E., Numans, M.E., Geerlings, M.I.,
2007. Estimating interaction on an additive scale between continuous
determinants in a logistic regression model. International Journal
of Epidemiology 36, 1111-1118.
I'm a bit surprised that you did not use the binomial "family" with a
probit link. The help page for ?family mentions the probit link as
appropriate for "normal CDF". It would seem possible to construct
competing models both with binomial errors and compare the deviance.
If you wanted to do this via embedding each model in a higher order
model where the degree of "multipicativity" was represented by a
parameter to be estimated, I remember that Breslow offered GLIM code
to perform that test in one of his two volumes. My copies are
temporarily in storage or I would have given a more specific citation.
N.E. Breslow & N. E. Day (1980) Statistical Methods in Cancer
Research. Volume I - The Analysis of Case-Control Studies
N.E. Breslow & N. E. Day (1987) Statistical Methods in Cancer
Research. Volume II - The Analysis of Cohort Studies
Wait ... I can do better. The entire chapter that I was remembering
appears to now be accessible online from the publisher's website:
http://www.iarc.fr/en/publications/pdfs-online/stat/sp82/SP82_vol2-4.pdf
________________________________
Van: sarahw [via R] [mailto:ml-node+s789695n464968...@n4.nabble.com]
Verzonden: vrijdag 16 november 2012 2:39
Aan: Peyrot, Wouter
Onderwerp: Re: additive interaction for a dichotomous dependent
variable (i.e. risk difference)
Did you ever get a response to this or resolve this yourself?
Many thanks!
________________________________
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discussion below:
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David Winsemius, MD
Alameda, CA, USA
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