Dear All
I am analysing the effect of a stable partnership (p.stable) adjusted for
other co-variates on the ability to work (abilityrr) in HIV infected
patients. Abilityrr has three ordinal categories (0,1,2) and I am modeling
this using a proportional odds model using Harrell's Design library.
Abilityrr does not seem to operate in an ordinal fashion with respect to
sex (m,f) and log.rna (continous variable). How would I need to treat these
co-variates in the model? Many thanks for your support!!!
Best wishes,
Pedram
Pedram Sendi, MD, DSc
Institute for Clinical Epidemiology & Division of Infectious Diseases
Institut fur klinische Epidemiologie & Abteilung fur Infektiologie
Basel University Hospital
Kantonsspital Basel
Hebelstrasse 10, 3rd Floor
CH-4031 Basel
Switzerland
Phone: +41 61 265 31 02
Fax: +41 61 265 31 09
E-Mail: psendi@uhbs.ch
-----Original Message-----
From: Frank E Harrell Jr [SMTP:fharrell@virginia.edu]
Sent: Wednesday, May 14, 2003 12:48 PM
To: psendi@uhbs.ch
Cc: s-news@lists.biostat.wustl.edu
Subject: Re: [S] comparing lrm models
On Wed, 14 May 2003 12:02:38 +0200
Pedram Sendi <psendi@uhbs.ch> wrote:
> Dear all
>
> I have two binary logistic regression models created with the lrm command
> from the Design library. Is there any analogon to the anova command for
> comparing glm models when using the Design library? As I understood, the
> anova.Design command cannot be used to compute LR statistics but Wald
> statistics.
>
> Thanks for any help.
> Pedram
>
> Pedram Sendi, MD, DSc
> Institute for Clinical Epidemiology & Division of Infectious Diseases
> Institut fur klinische Epidemiologie & Abteilung fur Infektiologie
> Basel University Hospital
> Kantonsspital Basel
> Hebelstrasse 10, 3rd Floor
> CH-4031 Basel
> Phone: +41 61 265 31 02
> Fax: +41 61 265 31 09
> E-Mail: psendi@uhbs.ch
>
Assuming the models are nested, lrtest(fit1,fit2) should do it. This also
assumes that the same sample sizes were used in both fits.
---
Frank E Harrell Jr Prof. of Biostatistics & Statistics
Div. of Biostatistics & Epidem. Dept. of Health Evaluation Sciences
U. Virginia School of Medicine http://hesweb1.med.virginia.edu/biostat
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