<?xml version="1.0" encoding="UTF-8"?>
<rss xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:taxo="http://purl.org/rss/1.0/modules/taxonomy/" version="2.0">
  <channel>
    <title>topic case matching and random selection for a case control study in Statistical Procedures</title>
    <link>https://communities.sas.com/t5/Statistical-Procedures/case-matching-and-random-selection-for-a-case-control-study/m-p/864162#M42724</link>
    <description>&lt;P&gt;I am trying to match based on gender and facility, but am running into trouble with repeated controls. Is there a way to specify that each control observation can only be picked once so I don't wind up with repeats? This is what I have so far and my dataset looks somewhat like this&lt;/P&gt;&lt;P&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;MRN&amp;nbsp;&amp;nbsp;&amp;nbsp; Gender&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; Facility&lt;/P&gt;&lt;P&gt;1&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 1&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; facility1&lt;/P&gt;&lt;P&gt;2&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 0&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; facility2&lt;/P&gt;&lt;P&gt;&amp;nbsp;&amp;nbsp;&lt;/P&gt;&lt;P&gt;PROC SQL;&lt;BR /&gt;CREATE table controls_id&lt;BR /&gt;as select&lt;BR /&gt;one.Gender as control_Gender,&lt;BR /&gt;two.Gender as case_Gender,&lt;BR /&gt;one.Facilitys as control_fac,&lt;BR /&gt;two.Facilitys as case_fac,&lt;BR /&gt;FROM control one, cases two&lt;BR /&gt;where ( one.Facilitys=two.Facilitys and one.Gender=two.Gender);&lt;/P&gt;&lt;P&gt;&lt;BR /&gt;proc sort data =controls_id out=controls_ids;&lt;BR /&gt;by control_id case_id ;&lt;BR /&gt;run;&lt;/P&gt;&lt;P&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;proc surveyselect data=controls_ids method=srs n=3 out=caseids;&lt;BR /&gt;strata control_id ;&lt;BR /&gt;SAMPLINGUNIT case_id;&lt;BR /&gt;run;&lt;/P&gt;</description>
    <pubDate>Tue, 14 Mar 2023 20:41:56 GMT</pubDate>
    <dc:creator>smoore3790</dc:creator>
    <dc:date>2023-03-14T20:41:56Z</dc:date>
    <item>
      <title>case matching and random selection for a case control study</title>
      <link>https://communities.sas.com/t5/Statistical-Procedures/case-matching-and-random-selection-for-a-case-control-study/m-p/864162#M42724</link>
      <description>&lt;P&gt;I am trying to match based on gender and facility, but am running into trouble with repeated controls. Is there a way to specify that each control observation can only be picked once so I don't wind up with repeats? This is what I have so far and my dataset looks somewhat like this&lt;/P&gt;&lt;P&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;MRN&amp;nbsp;&amp;nbsp;&amp;nbsp; Gender&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; Facility&lt;/P&gt;&lt;P&gt;1&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 1&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; facility1&lt;/P&gt;&lt;P&gt;2&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; 0&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; facility2&lt;/P&gt;&lt;P&gt;&amp;nbsp;&amp;nbsp;&lt;/P&gt;&lt;P&gt;PROC SQL;&lt;BR /&gt;CREATE table controls_id&lt;BR /&gt;as select&lt;BR /&gt;one.Gender as control_Gender,&lt;BR /&gt;two.Gender as case_Gender,&lt;BR /&gt;one.Facilitys as control_fac,&lt;BR /&gt;two.Facilitys as case_fac,&lt;BR /&gt;FROM control one, cases two&lt;BR /&gt;where ( one.Facilitys=two.Facilitys and one.Gender=two.Gender);&lt;/P&gt;&lt;P&gt;&lt;BR /&gt;proc sort data =controls_id out=controls_ids;&lt;BR /&gt;by control_id case_id ;&lt;BR /&gt;run;&lt;/P&gt;&lt;P&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;proc surveyselect data=controls_ids method=srs n=3 out=caseids;&lt;BR /&gt;strata control_id ;&lt;BR /&gt;SAMPLINGUNIT case_id;&lt;BR /&gt;run;&lt;/P&gt;</description>
      <pubDate>Tue, 14 Mar 2023 20:41:56 GMT</pubDate>
      <guid>https://communities.sas.com/t5/Statistical-Procedures/case-matching-and-random-selection-for-a-case-control-study/m-p/864162#M42724</guid>
      <dc:creator>smoore3790</dc:creator>
      <dc:date>2023-03-14T20:41:56Z</dc:date>
    </item>
    <item>
      <title>Re: case matching and random selection for a case control study</title>
      <link>https://communities.sas.com/t5/Statistical-Procedures/case-matching-and-random-selection-for-a-case-control-study/m-p/864299#M42734</link>
      <description>&lt;P&gt;Try adding the NODUPKEY option in the PROC SORT. Does that fix it?&lt;/P&gt;</description>
      <pubDate>Wed, 15 Mar 2023 14:41:46 GMT</pubDate>
      <guid>https://communities.sas.com/t5/Statistical-Procedures/case-matching-and-random-selection-for-a-case-control-study/m-p/864299#M42734</guid>
      <dc:creator>Zard</dc:creator>
      <dc:date>2023-03-15T14:41:46Z</dc:date>
    </item>
  </channel>
</rss>

