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From |
Taavi Lai <taavi.lai@ut.ee> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Newbie: Case selection problem |

Date |
Sat, 05 Feb 2005 17:43:41 +0200 |

Thanks, it solved the problem at hand.

But as you quite correctly assumed the next step I have to do is to identify all diagnose combinations that are there.

Suggestions?

Taavi

David Kantor wrote:

To Taavi Lai:

There are several way of doing this. Here's one.

Say you have a variable called diag for diagnosis, and suppose that you are looking for persons that have the combination of values 2,3 & 7. (Those may not be realistic diag values, but they will suffice for now.) Also suppose that you have personid to identify persons.

sort personid

egen byte hasdiag2 = max(diag==2), by(personid)

egen byte hasdiag3 = max(diag==3), by(personid)

egen byte hasdiag7 = max(diag==7), by(personid)

/* (And you could compact that sequence with a -foreach- if you prefer.) */

gen byte hascombination = hasdiag2 & hasdiag3 & hasdiag7

/* You could also ...

bysort personid: keep if _n==1

-- if you want to reduce to one observation per person.

(And it could go before the -gen byte hascombination-.)

*/

----

This detects that the person has at least the particular combination; it does not detect whether these are the ONLY diagnoses. You were not clear whether that was part of the problem. If it is, then

more needs to be done.

I hope this is helpful.

-- David

At 11:42 PM 2/4/2005 +0200, Taavi Lai wrote:

Could someone point me a way:

I have a list of people and their diagnoses. One person can have varying number of observations according to the number of diagnoses.

I need to identify people with specific combination of diagnoses.

Taavi Lai

David Kantor Institute for Policy Studies Johns Hopkins University dkantor@jhu.edu 410-516-5404 * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

-- Tervishoiu instituut Tartu Ülikool Ravila 19 Tartu 50411 GSM: 56663859 Fax: 7374192 e-mail: taavi.lai@ut.ee * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: Newbie: Case selection problem***From:*David Kantor <dkantor@jhu.edu>

**References**:**Re: st: Newbie: Case selection problem***From:*David Kantor <dkantor@jhu.edu>

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