Meta-Analysis of Raw Mean Differences.

Abstract

This article discusses the meta-analysis of raw mean differences. It presents a rationale for cumulating psychological effects in a raw metric and compares raw mean differences to standardized mean differences. Some limitations of standardization are noted, and statistical techniques for raw meta-analysis are described. These include a graphical device for decomposing effect sizes. Several illustrative data sets are analyzed.

Clinical and Structural Outcomes After Arthroscopic Repair of Full-Thickness Rotator Cuff Tears With and Without Platelet-Rich Product Supplementation: A Meta-analysis and Meta-regression

“…Meta-analyses were performed to statistically compare the PRPþ and PRPÀ treatment groups regarding the overall relative risk ratio of a retear developing. 24 Subgroup meta-analyses were also performed to compare the overall effect of PRP treatment on the relative risk of sustaining a retear using the same 6 covariates as outlined earlier. A relative risk ratio of greater than 1.0 indicated an increased risk of sustaining a retear in the PRPþ group, whereas a relative risk ratio of less than 1.0 indicated an increased risk of sustaining a retear in the PRPÀ group.…”

“…Meta-analyses were performed to statistically compare the PRPþ and PRPÀ treatment groups regarding pre-and postoperative clinical outcome scores. 24 The weighted mean pre-to postoperative change in outcome scores was also calculated and compared between the PRPþ and PRPÀ treatment groups. The relative gain in outcome scores (q) was defined as the pre-to postoperative change in the PRPþ group minus the pre-to postoperative change in the PRPÀ group.…”

Subclinical Hypothyroidism Impact on the Characteristics of Patients with Polycystic Ovary Syndrome. A Meta-Analysis of Observational Studies

“…Because the outcomes were reported on a meaningful same scale, the meta-analysis of enrolled studies was performed using the raw mean difference (RMD) [37]. Anthropometric, metabolic, and hormonal characteristics were compared between euthyroid PCOS and SCH-PCOS patients.…”

Subsistence strategy changes: The evidence of entheseal changes

“…Box plots with standard errors of means were plotted in the 64 bit version of the statistics package R version 2.15.1. Effect sizes were calculated to determine whether any differences between groups were meaningful (Bond et al, 2003;Field and Gillett, 2010). Two effect sizes were calculated using Eqs.…”