st: Re: RE: CASE-CONTROL STUDY

["Ishay Barat" <i.b@dadlnet.dk>]

Dear Kieran and David



There can be lots of arguments why one designs backwards study and not 
forward one. In my case, I am responsible for a lot of patients, going 
through my department, and need form time to time to have quality control of 
our patients management. It would have been nice to have a quarter of a 
million $ and 3 years time to carry on a study, but that's not reality.



Sorry.



And now for your question.



As my objective is geriatric patients, and my data includes general inter 
medicine ward cliental I like to reduce the noise younger and far healthier 
patients introduces into my data.

By matching some crucial parameters like age, sex, medication and disease, I 
may get answers to my questions.



As to my anagram. It is just for fun and nothing else.



As to the reference to 
http://personalpages.manchester.ac.uk/staff/mark.lunt/optmatch.html

I installed the files, but can not find the command in the menus.




*¸..· ´¨)) -:¦:-        *
   ¸.·´ .
 (( -:¦:- * Ishay *  -:¦:-
   ´·..          ..·´
              ((¸¸.·´* -:¦:-

_________________________________________________________-


> Matching is an element of the design of a study, planned before the data 
> is collected, and should be done for efficiency, not control.
> If you already have the data, you gain nothing by matching.  You have a 
> sample size of 2,500.  If you match these data in the way you have 
> indicated, you will end up with a matched sample size of 1,200.  Why would 
> you want to discard over half of your data?
>
> You should analyse the data as they are and control for age, sex, etc in 
> the analysis.
>
>
> ______________________________________________
> Kieran McCaul MPH PhD
> WA Centre for Health & Ageing (M573)
> University of Western Australia
> Level 6, Ainslie House
> 48 Murray St
> Perth 6000
> Phone: (08) 9224-2140
> Fax: (08) 9224 8009
> email: kamccaul@meddent.uwa.edu.au
> http://myprofile.cos.com/mccaul
> http://www.researcherid.com/rid/B-8751-2008
> ______________________________________________
> Epidemiology is so beautiful and provides such an important perspective on 
> human life and death,
> but an incredible amount of rubbish is published.  Richard Peto (2007)
>
> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu 
> [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Ishay Barat
> Sent: Sunday, 15 March 2009 1:28 AM
> To: statalist@hsphsun2.harvard.edu
> Subject: st: CASE-CONTROL STUDY
>
> HELLO
>
>
>
> I've got a data set containing about 2500 patients, of which 300 have my
> interest (Group A).
>
> I would like to extract a sample of 900 patients (Group B) out of the data
> set that match Group A in age, sex and some other parameters. A Classical
> Case-Control study with 3 controllers for each case.
>
>
>
> Is anybody have a clue how the syntax look like??
>
>
>
>
>
>
> *¸..· ´¨)) -:¦:-        *
>    ¸.·´ .
>  (( -:¦:- * Ishay *  -:¦:-
>    ´·..          ..·´
>               ((¸¸.·´* -:¦:-
>
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