Rod
there is a literature on this - for a review see
Dumville, J., Hahn, S., Miles, J. & Torgerson, D. (2006). The use of unequal
randomisation ratios in clinical trials: a review. Contemporary Clinical
Trials, 27, 1-12.
.
Frances
Dr Frances Gardner, Professor of Child and Family Psychology
Department of Social Policy & Social Work, Oxford University
32 Wellington Square, Oxford OX1 2ER, UK
tel:44-1865-270334 [log in to unmask]
In message
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k> "Campbell Rod (5N6) Derbyshire County PCT"
<[log in to unmask]> writes:
> Hi
> We are looking at a trial for sibutramine plus behavioural therapy for
> adolescent obesity.
> Article:
> http://www.annals.org/cgi/content/abstract/145/2/81
> <http://www.annals.org/cgi/content/abstract/145/2/81>
> The design statement says "12 month, 3:1 randomized db trial". that is
> the treatment arm is 3 times the size of the control.
> In my experience most trials have arms that are similar in size.
> What are the problems if any of (considerably) unequal size?
> Regards
> Rod
> R.M. Campbell
> Knowledge Manager
> Knowledge Services
> Derbyshire County PCT
> Babington Hospital
> Derby Road
> Belper
> Derbyshire
> DE56 1WH
>
> 01773 525059
> [log in to unmask]
> http://nww.derbyshirecountypct.nhs.uk/knowledge-services.asp
>
> <http://dtb.bmj.com/>
> --
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