  Hi all,

I am analyzing longitudinal data, and I'm working around on the choice 
between a covariance model and a mixed model
to account for baseline,carryover , individual effects. The choice does  
not appear  so easy to me.
see for example, a recent thread on the topic:

Reformat: Assistance with specification of crossover design model
http://permalink.gmane.org/gmane.comp.lang.r.lme4.devel/11988

The following well-known paper advocates for  covariance model   
compared to change score model :
Vickers, A.J. & Altman, D.G. : Analysing controlled clinical trials with 
baseline and follow-up measurements.
British Medical Journal 2001; 323 : 1123-24.,

It  would be interesting  to run a mixed model on the data this 
(meta)study was based on, i.e:

Kleinhenz ,Streitberger K,Windeler J,Gussbacher A,Mavridis G, Martin E.
Randomised clinical trial comparing the effects of acupuncture and a 
newly designed placebo needle in rotator cuff 
tendonitis.Pain1999;83:235--241.
<http://www.bmj.com/lookup/external-ref?access_num=10.1016/S0304-3959%2899%2900107-4&link_type=DOI>
a) Maybe this comparaison  has been already done  with these data , so 
thank you for pointing me to a reference.
(I failed to find it  )
b) if not, are these data available somewhere ?  Several (meta)studies 
mentionned these data ,
so maybe these data could already  be included in a package  or 
somewhere else ?

Thank you very much for your help.

Robert Espesser

-- 
Robert Espesser
CNRS UMR  7309 - Université Aix-Marseille
5 Avenue Pasteur
13100 AIX-EN-PROVENCE

Tel: +33 (0)413 55 36 26


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