Re: st: Event within dates

[David Kpento <dkpento@yahoo.com>]

Thanks for the approach. But I am sorry when I tried it I got an error message invalid syntax.


----- Original Message -----
From: David Kantor <kantor.d@att.net>
To: statalist@hsphsun2.harvard.edu
Cc: 
Sent: Thursday, 1 December 2011, 20:51
Subject: Re: st: Event within dates

The following might work. It is an attempt to fill in some features 
that were needed in your method.
But it is somewhat brute-force in its approach. It does looping over 
observations (doubly), which is rarely needed.
There is probably a much better way to do this (involving -by-, for 
one), but this is all I can do at the moment.
HTH
--David


forval i = 1/ `N' {
         forval j = 1/ `N' {
                 replace rs1=1 if drug[`i]==1 & id[`i']==id[`j']  & 
inrange(date[`i'] - date[`j'],-56,56) in `i'
         }
}


At 02:15 PM 12/1/2011, David Kpento wrote:
>I have prescription data in panel format for analysis. I wish to 
>generate an indicator rs to be 1 for any subject who took drug2 
>within 56 days of taking drug1 (either before or after). Could 
>somebody please help me with any code? I am new to Stata so have 
>struggled with this for days.
>
>
>
>I use Stata/SE 9.0 for Windows.
>
>Many thanks
>
>David
>clear
>input id str9 date drug rs
>1 08apr2009 1 0
>1 08may2009 1 0
>1 08jun2009 2 1
>2 02jan2009 1 0
>2 28jan2009 2 1
>2 05apr2009 1 0
>3 07jan2009 2 1
>3 22mar2009 1 0
>3 02jul2009 1 0
>end
>
>I have a code like this after formatting the date into a Stata date 
>but rs1 is all zeros.
>
>gen date1 = date(date, "dmy")
>format date1 %d
>drop date
>rename date1 date
>
>g rs1=0
>local N=_N
>forval i = 1/ `N' {
>replace rs1=1 if drug==1 & id[`i'] & inrange(date[`i'] - date,-56,56) in `i'
>}

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