Date: Fri, 17 Dec 1999 18:56:54 GMT
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
Organization: Deja.com - Before you buy.
Subject: Re: analysis of 4 period cross-over design (placebo controlled,
Dear Mr. Joshy:
It would seem to me that finding a way to save your trial given the
difficulties you have encountered is more a problem in the domain of
epidemiologic methodology. I would therefore recommend that you post
this interesting question to EPIDEMIO-L: The Epidemiological Methods
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I look forward to seeing your post and the ensuing discussion on
Epidemio_L. Good luck!
Division of Clinical Epidemiology
Mcgill University Health Centre
Royal Victoria Hospital Pavilion
In article <9779D242E943D311AF1E0090278CABD4037951@ntsg46.novo.dk>,
"GJOS (Grace Joshy)" <GJOS@NOVO.DK> wrote:
> I'm trying to analyse a 12 patient randomised placebo controlled
> dose-response trial. The trial had 4 treatments administered on four
> days to each patient. It was intended to be latin-square design with 4
> different sequences, each repeated 3 times. The primary endpoint is
> of 4 hr blood glucose.
> But something went wrong in the randomisation procedure and the there
> different sequences with no blocking in the trial now.
> Any ideas for analysis that could save the trial?
> Is something like the SAS code below valid?
> proc mixed data=trial order=internal;
> class subj_id dose ;
> model lauc = dose/e;
> repeated / type=cs sub=subj_id r ;
> contrast 'Placebo vs Active'
> -3 1 1 1 ;
> estimate 'Active vs. Placebo' dose -1 0.33 0.33 0.33/ cl;
> lsmeans dose/e cov cl;
> make 'lsmeans' out=ls_mod2;
> Thanks & regds,
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