[R-meta] Meta-analysis including multiple intervention arms

[Ioana Cristea]

Thank you, that's what I thought!
Best
Ioana

On Sat, Nov 14, 2020 at 4:29 PM James Pustejovsky <jepusto using gmail.com> wrote:

> The short answer is no. If you are using RVE with a correlated effects
> working model, the (assumed) correlation between the effect sizes from each
> intervention arm takes care of the issue. Splitting the control sample size
> would over-correct, so that the study would end up with less weight than it
> should receive.
>
> James
>
> > On Nov 14, 2020, at 8:44 AM, Ioana Cristea <
> ioana.alina.cristea using gmail.com> wrote:
> >
> > Dear all
> > I am doing a meta-analysis of randomized trials where some trials have
> > multiple outcomes of interest (depression measured with different scales)
> > and a few have more than one active arms, usually 2 intervention arms and
> > control (therapy A compared to control, therapy B compared to control).
> > I am using robust variance estimator. My question is: for the cases where
> > there are multiple active intervention arms in a trial, compared to the
> > same control arm, should I adjust the sample size of the control arm (ie,
> > splitting by 2 if there are 2 active interventions compared to control)?
> > Thank you
> > Ioana
> >
> > --
> > Ioana-Alina Cristea, Ph.D.
> > Assistant Professor
> > Department of Brain and Behavioral Sciences
> > University of Pavia, Piazza Botta 11, 27100 Pavia, Italy
> >
> > Research affiliate
> > METRICS (Meta-research Innovation Center at Stanford)
> > Stanford University, California, USA
> > Editorial Advisory Board Lancet Psychiatry
> > <https://www.thelancet.com/journals/lanpsy/home>
> > International Editorial Board BJPsych Open
> > <https://www.cambridge.org/core/journals/bjpsych-open>
> >
> > ORCid: http://orcid.org/0000-0002-9854-7076
> > Publons: https://publons.com/author/1196647/ioana-alina-cristea#profile
> > Researchgate: https://www.researchgate.net/profile/Ioana_Cristea
> > Twitter: https://twitter.com/IoanaA_Cristea
> >
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> >
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>


-- 
Ioana-Alina Cristea, Ph.D.
Assistant Professor
Department of Brain and Behavioral Sciences
University of Pavia, Piazza Botta 11, 27100 Pavia, Italy

Research affiliate
METRICS (Meta-research Innovation Center at Stanford)
Stanford University, California, USA
Editorial Advisory Board Lancet Psychiatry
<https://www.thelancet.com/journals/lanpsy/home>
International Editorial Board BJPsych Open
<https://www.cambridge.org/core/journals/bjpsych-open>

ORCid: http://orcid.org/0000-0002-9854-7076
Publons: https://publons.com/author/1196647/ioana-alina-cristea#profile
Researchgate: https://www.researchgate.net/profile/Ioana_Cristea
Twitter: https://twitter.com/IoanaA_Cristea

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