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Re: st: complex generating criteria


From   Svend Juul <SJ@SOCI.AU.DK>
To   <statalist@hsphsun2.harvard.edu>
Subject   Re: st: complex generating criteria
Date   Thu, 16 Oct 2008 21:48:50 +0200

sham wrote:
 
I'm working on a dataset that has recorded the drug 
treatment and their response for a number of patients 
over one year.
 
however to assign them one of 3 "improved responses" 
there is a standard definition.

That is a improvement of 30% (a percentage increase) 
in 3 of any 6 clinical variables and a decrease in no 
more than 1. this gives them a  criteria of "acr30".
 
In addition to this, I also wish to create improvement 
of 50% and 70%, and combine them into one categorical variable.
I was wondering what the best way of doing this would be?
 
=========================================================
 
In the following example I assume that the response variables
are before1, after1, before2, ... , after6.
 
     // calculate number of increases > 30% (inc30) and decreases
     generate inc30=0   // increased more than 30%
     generate decr=0    // decreased
     forvalues I = 1/6 {
        replace inc30=inc30+1 if after`I' > 1.3*before`I' & after`I'<.
        replace decr = decr+1 if after`I' < before`I'
     }
 
     // Improved according to criteria
     generate improved = inc30>2 & inc30<. & decr==0
 
Hope this helps
Svend
 
________________________________________________________ 
 
Svend Juul
Institut for Folkesundhed, Afdeling for Epidemiologi
(Institute of Public Health, Department of Epidemiology)
Vennelyst Boulevard 6 
DK-8000 Aarhus C,  Denmark 
Phone, work:   +45 8942 6090 
Phone, home:   +45 8693 7796 
Fax:           +45 8613 1580 
E-mail:        sj@soci.au.dk 
_________________________________________________________ 

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