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From | David Kpento <dkpento@yahoo.com> |
To | "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |
Subject | Re: st: Event within dates |
Date | Thu, 1 Dec 2011 22:34:09 +0000 (GMT) |
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' >} * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/