Does the group in group psychotherapy matter? A meta-analysis of the intraclass correlation coefficient in group treatment research.

OBJECTIVE: Over the last 3 decades, group treatment researchers have become increasingly knowledgeable of the impact of within-group dependency on analyses of group treatment data and of mutual influence processes that occur within therapy groups. Despite these advancements, there remains a lack of consensus on the magnitude of mutual influence, or group effects, in group treatment research. As such, this study sought to estimate the size of group effects on members' posttreatment outcomes by meta-analyzing the intraclass correlation coefficients (ICCs) in group treatment research. In addition, we tested several moderators of the ICC, including outcome type, outcome reactivity, outcome specificity, group format, treatment length, and group size. METHOD: Using robust variance estimations, we meta-analyzed 169 effect sizes from 37 group treatment studies. RESULTS: Findings indicated an average ICC of 0.06. Group size, group format, treatment length, outcome specificity, and outcome type did not significantly moderate the ICC; however, we did find evidence to suggest that the ICC varies as a function of outcome reactivity, with observer-rated outcome measures resulting in the largest ICC. CONCLUSION: These findings suggest that interdependence in group treatment research is an important concept both theoretically and statistically. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Construction and validation of the Multicultural Orientation Inventory-Group Version.

Given the continued racial/ethnic diversification of the United States, it is not uncommon for therapy groups to consist of members with diverse racial/ethnic backgrounds and various cultural identities. Scholars have underscored how this cultural diversity can directly impact many processes and outcomes of group-based interventions (Chen, Kakkad, & Balzano, 2008). However, there is presently a paucity of empirical research testing the relationship between cultural processes of therapy groups and members' outcomes. Moreover, no psychometrically sound measure of the cultural process that unfolds in group therapy currently exists. As such, this study sought to adapt the Multicultural Orientation Inventory to develop and validate the Multicultural Orientation Inventory-Group Version (MCO-G), a measure assessing the cultural humility, cultural comfort, and cultural missed opportunities in therapy groups. Data for this validation study consisted of 208 members of 49 therapy groups across 10 university counseling centers. Confirmatory factor analyses supported a 3-factor structure of the MCO-G Inventory, wherein the 3 factors corresponded with the underlying constructs of cultural humility, cultural comfort, and cultural missed opportunities. This study provides initial evidence for the estimated internal and convergent validity of the MCO-G, as measured by clients' perceptions of a higher-order group therapeutic factor and improvement in therapy. Results provide initial support for the psychometric properties of the MCO-G. Moreover, groups' cultural humility and cultural missed opportunities were related to members' improvement in therapy. Clinical implications and future research are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).