# Calculating Orwin's (1983) modified Fail-safe N in a meta-analysis with Odds Ratio as summary statistic?

I am attempting to calculate Orwin's (1983) modification of Rosenthal's (1979) Fail-safe N for my meta-analysis of Odds Ratios.

However, all the equations I am finding are using Cohen's d, which I cannot calculate (I don't have two groups).

I have STATA, SPSS, and MedCalc at my disposal.

Normally you always find ways to convert effect size. For example you can calculate $r$ from $d$ and back. So you surely will be able to converts odds ratio to Cohen's $d$.