Continuous-outcome meta-analysis pools per-study means, SDs and group sizes, giving Hedges' g (SMD) by default, with mean difference and log ratio of means also available.
When the original studies report mean ± SD with n per arm, the effect size + SE can be computed mechanically — Hedges' g is the standardised mean difference (Cohen's d with a small-sample correction). Pooling SMDs across studies is the standard approach when the original outcomes are on different scales (e.g. several depression-rating instruments).
Mean difference (MD) is the alternative when all studies share the same outcome scale; report MD over SMD whenever possible because MDs are interpretable in the outcome's units.
Six numeric columns: mean / SD / n for each arm + optional study labels.
Same as meta_iv with the effect size + SE derived internally.
Prefer MD when all studies use the same instrument (more interpretable); SMD when instruments differ. Report Hedges' g rather than Cohen's d for small-sample-corrected estimation.