Analogously to the IVW method, we suggest using the inverse of the variance of the ratio estimates as weights: wj′=γ^j2σYj2.These weights are derived from the delta method for the variance of the ratio of two random variables, and represent the reciprocal of the variance of the ratio estimates (the inverse‐variance weights) (Thomas et al., 2007). Standardized weights are wj=wj′∑jwj′. The unstandardized weights are identical to those used in the IVW estimator. Only the first‐order term from the delta expansion is used here; further terms could be considered, although we found that they did not affect estimates or standard errors from the weighted median method substantially.
