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    <title>topic Re: drop out rate in proc seqdesign in Statistical Procedures</title>
    <link>https://communities.sas.com/t5/Statistical-Procedures/drop-out-rate-in-proc-seqdesign/m-p/486171#M25176</link>
    <description>&lt;P&gt;The dropout rate were also&amp;nbsp;converted to group loss hazards in the same way. Therefore, the 5% dropout rate for 70 months duration was corresponding to the group loss hazard of -ln(1-dropout rate)/StudyDuration =-ln(1-0.05)/70= 0.00073.&lt;/P&gt;</description>
    <pubDate>Sun, 12 Aug 2018 17:06:21 GMT</pubDate>
    <dc:creator>windfor</dc:creator>
    <dc:date>2018-08-12T17:06:21Z</dc:date>
    <item>
      <title>drop out rate in proc seqdesign</title>
      <link>https://communities.sas.com/t5/Statistical-Procedures/drop-out-rate-in-proc-seqdesign/m-p/413404#M21668</link>
      <description>&lt;P&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;Hi,&lt;/P&gt;&lt;P&gt;I need some help figuring out how to use the loss=exp(hazard=hazard rate) option in proc seqdesign correctly.&amp;nbsp; If the trial is expected to have 10% drop out total, but most is early (within 4 months of randomization), what's the proper (or best) way to calculate the hazard rate?&amp;nbsp; Any help vastly appreciated.&lt;/P&gt;&lt;P&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;swannie&lt;/P&gt;&lt;P&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;&lt;FONT color="#0000ff" face="Courier New" size="2"&gt;%let&lt;/FONT&gt;&lt;FONT face="Courier New" size="2"&gt; drop_out=0.0027;&lt;/FONT&gt;&lt;/P&gt;&lt;P&gt;ods graphics on;&lt;/P&gt;&lt;P&gt;proc seqdesign plots=boundary(hscale=samplesize) boundaryscale=stdz errspend ;&lt;/P&gt;&lt;P&gt;&lt;FONT face="Courier New" size="2"&gt;OneSidedOBrienFleming: design nstages=&lt;/FONT&gt;&lt;STRONG&gt;&lt;FONT color="#008080" face="Courier New" size="2"&gt;2&lt;/FONT&gt;&lt;/STRONG&gt;&lt;FONT face="Courier New" size="2"&gt; method=errfuncobf alpha=&lt;/FONT&gt;&lt;STRONG&gt;&lt;FONT color="#008080" face="Courier New" size="2"&gt;0.02&lt;/FONT&gt;&lt;/STRONG&gt;&lt;FONT face="Courier New" size="2"&gt; alt=upper beta=&lt;/FONT&gt;&lt;STRONG&gt;&lt;FONT color="#008080" face="Courier New" size="2"&gt;0.10&lt;/FONT&gt;&lt;/STRONG&gt;&lt;FONT face="Courier New" size="2"&gt; info=cum(&lt;/FONT&gt;&lt;STRONG&gt;&lt;FONT color="#008080" face="Courier New" size="2"&gt;0.50&lt;/FONT&gt;&lt;/STRONG&gt; &lt;STRONG&gt;&lt;FONT color="#008080" face="Courier New" size="2"&gt;1&lt;/FONT&gt;&lt;/STRONG&gt;&lt;FONT face="Courier New" size="2"&gt;) stop=both(betaboundary=nonbinding);&lt;/FONT&gt;&lt;/P&gt;&lt;P&gt;&lt;FONT face="Courier New" size="2"&gt;samplesize model(ceiladjdesign=include)=twosamplesurvival (nullhazard=&lt;/FONT&gt;&lt;STRONG&gt;&lt;FONT color="#008080" face="Courier New" size="2"&gt;0.0608&lt;/FONT&gt;&lt;/STRONG&gt;&lt;FONT face="Courier New" size="2"&gt; hazard=&lt;/FONT&gt;&lt;STRONG&gt;&lt;FONT color="#008080" face="Courier New" size="2"&gt;0.0385&lt;/FONT&gt;&lt;/STRONG&gt;&lt;FONT face="Courier New" size="2"&gt; weight= &lt;/FONT&gt;&lt;STRONG&gt;&lt;FONT color="#008080" face="Courier New" size="2"&gt;1&lt;/FONT&gt;&lt;/STRONG&gt; &lt;STRONG&gt;&lt;FONT color="#008080" face="Courier New" size="2"&gt;1&lt;/FONT&gt;&lt;/STRONG&gt;&lt;FONT face="Courier New" size="2"&gt; accrual=uniform acctime=&amp;amp;&lt;/FONT&gt;&lt;FONT color="#008080" face="Courier New" size="2"&gt;rectime.&lt;/FONT&gt;&lt;FONT face="Courier New" size="2"&gt; loss=exp(hazard=&amp;amp;&lt;/FONT&gt;&lt;FONT color="#008080" face="Courier New" size="2"&gt;droprate.&lt;/FONT&gt;&lt;FONT face="Courier New" size="2"&gt;) totaltime=&amp;amp;&lt;/FONT&gt;&lt;FONT color="#008080" face="Courier New" size="2"&gt;total_time.&lt;/FONT&gt; &lt;FONT face="Courier New" size="2"&gt;ceiling=n);&lt;/FONT&gt;&lt;/P&gt;&lt;P&gt;run;&lt;/P&gt;&lt;P&gt;ods graphics off;&lt;/P&gt;&lt;P&gt;&amp;nbsp;&lt;/P&gt;</description>
      <pubDate>Tue, 14 Nov 2017 16:55:34 GMT</pubDate>
      <guid>https://communities.sas.com/t5/Statistical-Procedures/drop-out-rate-in-proc-seqdesign/m-p/413404#M21668</guid>
      <dc:creator>swannie</dc:creator>
      <dc:date>2017-11-14T16:55:34Z</dc:date>
    </item>
    <item>
      <title>Re: drop out rate in proc seqdesign</title>
      <link>https://communities.sas.com/t5/Statistical-Procedures/drop-out-rate-in-proc-seqdesign/m-p/486171#M25176</link>
      <description>&lt;P&gt;The dropout rate were also&amp;nbsp;converted to group loss hazards in the same way. Therefore, the 5% dropout rate for 70 months duration was corresponding to the group loss hazard of -ln(1-dropout rate)/StudyDuration =-ln(1-0.05)/70= 0.00073.&lt;/P&gt;</description>
      <pubDate>Sun, 12 Aug 2018 17:06:21 GMT</pubDate>
      <guid>https://communities.sas.com/t5/Statistical-Procedures/drop-out-rate-in-proc-seqdesign/m-p/486171#M25176</guid>
      <dc:creator>windfor</dc:creator>
      <dc:date>2018-08-12T17:06:21Z</dc:date>
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