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Re: st: date of last follow up
From
Nick Cox <[email protected]>
To
[email protected]
Subject
Re: st: date of last follow up
Date
Tue, 13 Sep 2011 08:14:34 +0100
Richard says everything you need to know on this, but see also
FAQ . . . . . . . . . . . . . . . . . . . . . . . Generating the last date
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox
4/05 How can I generate a variable containing the last of
several dates?
http://www.stata.com/support/faqs/data/lastdate.html
bysort subjectid (visitdate) : gen maxvstdate = visitdate[_N]
would be equivalent for numeric dates, none of which were missing.
Nick
On Tue, Sep 13, 2011 at 7:54 AM, Richard Goldstein
<[email protected]> wrote:
> if visitdate is a Stata date (see -h dates-), then just go
>
> egen maxvstdate = max(visitdate), by(subjectid)
>
> if visitdate is not a Stata date (e.g., it is a string), then make into
> a Stata date (-h dates-)
>
> Rich
>
> On 9/13/11 12:33 AM, Michael Eisenberg wrote:
>> I'd like some help working with dates in Stata.
>>
>> I have a list of visits for several patients. I'd like to make a
>> column which lists the date they were last seen. In other words, a
>> date of last follow up.
>>
>> I'm fairly certain I need to start with a bysort command, but I'm not
>> sure what should come next.
>>
>> My data looks as follows.
>>
>> subjectid test visitdate
>> 1 r 1-3-2010
>> 1 q 2-1-2009
>> 1 e 6-3-2011
>> 2 q 2-1-2006
>> 2 e 6-3-2008
>> 3 r 1-3-2005
>> 4 q 2-26-2009
>> 4 e 6-13-2011
>> 4 r 10-23-2010
>> 2 q 2-15-2007
>> 1 e 6-30-2004
>>
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