</span>, <span class="fu">.</span><span class="op">(</span><span class="va">mcid</span>, <span class="va">start</span><span class="op">)</span><span class="op">]</span></span>
<span></span>
<span><span class="co"># Filter by program on start</span></span>
<span><span class="va">join_labels</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/pkg/data.table/man/copy.html" class="external-link">copy</a></span><span class="op">(</span><span class="va">study_programs</span><span class=