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Re: st: Calculating Prevalence


From   Raphael Fraser <raphael.fraser@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Calculating Prevalence
Date   Wed, 31 Aug 2005 16:19:39 -0500

Many thanks. I should have known better. 

On 8/31/05, Clive Nicholas <Clive.Nicholas@newcastle.ac.uk> wrote:
> Raphael Fraser wrote:
> 
> > I have 50 data sets (d1, d2, ..., d50) like the one given below but
> > much larger. I would like to calculate the prevalence of protein for
> > each data set by genotype (AA and SS). Then put the results together
> > in a single file. Can this be done?
> >
> >
> > DATA SET 1(d1)
> > id            age     genotype   protein
> > 31            11      AA             1
> > 40            11      SS             0
> > 71            11      AA             1
> > 74            11      AA             0
> > 88            11      AA             0
> > 98            11      AA             0
> > 110          11      SS             1
> >
> > The first two observation in the RESULTS file should look some thing like
> > this:
> >
> >  age   genotype  prevalence
> >   11         AA          0.4
> >   11         SS          0.5
> 
> Looks like an easy job for -collapse-, thus:
> 
> . collapse (mean) age protein, by(genotype)
> 
> You have to discard your -id- variable for this to work. I assume you mean
> -protein- when you say -prevalance-, in which case you can easily
> -rename-. I hope this helps.
> 
> CLIVE NICHOLAS        |t: 0(044)7903 397793
> Politics              |e: clive.nicholas@ncl.ac.uk
> Newcastle University  |http://www.ncl.ac.uk/geps
> 
> Whereever you go and whatever you do, just remember this. No matter how
> many like you, admire you, love you or adore you, the number of people
> turning up to your funeral will be largely determined by local weather
> conditions.
> 
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> 


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