urvreg</a></span><span class="op">(</span>formula <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/pkg/survival/man/Surv.html" class="external-link">Surv</a></span><span class="op">(</span><span class="va">AVAL_OS</span><span class="op">/</span><span class="fl">365.25</span>, <span class="va">Event_OS</span><span class="op">)</span> <span class="op">~</span> <span class="va">ARMCD</span>, data <span class="op">=</span> <span class="va">IPD</span>, dist <span class="op">=</span> <span clas