Methodological analysis reveals superior performance of pre-post change differences standardized by pooled pretest variance, highlighting improved precision for repeated-measures trials.
Previous research has recommended several measures of effect size for studies with repeated measurements in both treatment and control groups. Three alternate effect size estimates were compared in terms of bias, precision, and robustness to heterogeneity of variance. The results favored an effect size based on the mean pre-post change in the treatment group minus the mean pre-post change in the control group, divided by the pooled pretest standard deviation.
No takes yet. Share an insight, caveat, or question.
Scott B. Morris (2007) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: