What is the inverse variance method for pooling weighted mean differences?
The inverse variance method for pooling weighted mean differences is a statistical technique used to combine the results of multiple studies in a meta-analysis. This method allows for the comparison of different study designs, such as randomized controlled trials, observational studies, and case-control studies. The inverse variance method estimates the overall effect size in a meta-analysis by calculating the weighted average of the effect size estimates from each study. The weight assigned to each study is based on the inverse of the variance of the effect size, which is a measure of the precision of the effect size estimate. This method provides a more accurate estimate of the overall effect size compared to other methods, such as fixed-effect models and random-effects models. It is especially useful when the studies included in the meta-analysis are heterogeneous, meaning they have different designs, sample sizes, and study populations.  