class="op">[[</span><span class="fl">1</span><span class="op">]</span><span class="op">]</span><span class="op">)</span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span>    lhs op   rhs    est    se      z pvalue ci.lower ci.upper</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1 1432  ~ group -0.017 0.072 -0.240  0.810   -0.157    0.123</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2 1616  ~ group  0.105 0.079  1.329  0.184   -0.