I am preparing a meta-analysis for a certain therapeutic intervention, and will be interested to quantify/summarise the change in various scores, pre-to-post intervention.
Which measure of effect size should I use, namely the effect size that I extract or compute from primary papers, and also that I later compute as a summary measure? I am not sure on which grounds to choose among the main choices:
OR (the odds ratio)
SMD (standardized mean difference)
Cohen's d is I guess most typically reported in papers so makes life a bit easier. On the other hand, some papers recommend ORs, although not over Cohen's d but over correlation coefficients.
Are some measures of effect sizes more suitable for some meta-analyses but not for others, e.g. those that look at the effect of an intervention (longitudinal) vs those that do a cross-sectional comparison?