[R] calculate power-linear mixed effect model

Bert Gunter bgunter@4567 @end|ng |rom gm@||@com
Fri Sep 17 22:20:02 CEST 2021

```Note that such info is available at
https://www.r-project.org/mail.html  (under "Special Interest
Groups").
IMHO the posting guide ought to prominently say something about this.

Cheers,
Bert

On Fri, Sep 17, 2021 at 1:10 PM Ana Marija <sokovic.anamarija using gmail.com> wrote:
>
> Thank you so much for that info!
>
> On Fri, Sep 17, 2021 at 3:06 PM Bert Gunter <bgunter.4567 using gmail.com> wrote:
> >
> > Wrong list! Post on r-sig-mixed-models, not here.
> >
> > Bert Gunter
> >
> > "The trouble with having an open mind is that people keep coming along
> > and sticking things into it."
> > -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
> >
> > On Fri, Sep 17, 2021 at 12:22 PM Ana Marija <sokovic.anamarija using gmail.com> wrote:
> > >
> > > Hi All,
> > >
> > > I plan to identify metabolite levels that differ between individuals
> > > with various retinopathy outcomes (DR or noDR). I plan to model
> > > metabolite levels using linear mixed models ref as implemented in
> > > lmm2met software. The model covariates will include: age, sex, SV1,
> > > SV, and disease_condition.
> > >
> > > The random effect is subject variation (ID)
> > >
> > > Disease condition is the fixed effect because I am interested in
> > > metabolite differences between those disease conditions.
> > >
> > > This command  will build a model for each metabolite:
> > > fitMet = fitLmm(fix=c('Sex','Age','SV1,'SV2','disease_condition'),
> > > random='(1|ID)', data=df, start=10)
> > >
> > > SV1 and SV2 are surrogate variables (numerical values)
> > >
> > > Next I need to calculate the power of my study. Let's say that I have
> > > 1,172 individuals total in the study, from which 431 are DR. Let's say
> > > that I would like to determine the power of this study given the
> > > effect size of 0.337.
> > >
> > > I know about SIMR software in R but I am not sure how to apply it to
> > > my study design.
> > >
> > > I looked at this paper:
> > > https://besjournals.onlinelibrary.wiley.com/doi/10.1111/2041-210X.12504
> > >
> > > But I am not sure how to adapt the code given in the tutorial so that
> > > it is matching to mine design.
> > >
> > > Can you please help,
> > >
> > > Thanks
> > > Ana
> > >
> > > ______________________________________________
> > > R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > > https://stat.ethz.ch/mailman/listinfo/r-help
> > > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> > > and provide commented, minimal, self-contained, reproducible code.

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