ebo controlled trial of gamma interferon in Chronic Granulomatous
Disease.</p>
<p>In this example the <code>treatment</code> column contains the
intervention.</p>
<p>For the analysis we are considering only the first observations for
each patient, and our study criteria are as follows:</p>
<ul>
<li>Only patients from US based centres are considered</li>
<li>Patients must not be on steroids at inception.</li>
<li>Patients must be aged between the ages of 5 and 35 inclusive.</li>
</ul>
<p>This can be coded in