st: Event within dates

[David Kpento <dkpento@yahoo.com>]

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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