de>.</p>
</dd>
<dt><code>subject</code></dt><dd><p>the patient ID, a factor with levels <code>1</code> to
<code>111</code>.</p>
</dd>
</dl>



<h3>Details</h3>

<p>In each of two centres, eligible patients were randomly assigned 
to active treatment or placebo. During the treatment, the respiratory
status (categorised <code>poor</code> or <code>good</code>) was determined at each
of four, monthly visits. The trial recruited 111 participants
(54 in the active group, 57 in the placebo group) and there were
no