Log odds ratio
= Log odds ratio
{title2=$\log\operatorname{OR}$}
The log odds ratio is the <natural logarithm> of an <odds ratio>. For two <independent> binomial groups with positive event and non-event counts $(a,b)$ and $(c,d)$, its estimate is $\log(ad/(bc))$, with first-order <variance> $1/a+1/b+1/c+1/d$ by the <delta method>. Zero cells need a method that handles boundary data; the displayed normal approximation is not valid there.