, this is
<code>4 / (1 / n_control + 1 / n_case)</code>; in the case of a meta-analysis, you
should sum the effective sample sizes of each study instead of using the
total numbers of cases and controls, see <a href="https://doi.org/10.1016/j.biopsych.2022.05.029" class="external-link">doi:10.1016/j.biopsych.2022.05.029</a>
;
when using a mixed model, the effective sample size needs to be adjusted
as well, see <a href="https://doi.org/10.1016/j.xhgg.2022.100136" class="external-link">doi:10.1016/j.xhgg.2022.