Assessing the alliance-outcome association adjusted for patient characteristics and treatment processes : a meta-analytic summary of direct comparisons / Christoph Fluckiger [and five others]

Includes bibliographical references (pages 710-711).

The alliance is widely recognized as a robust predictor of posttreatment outcomes. However, there is a debate regarding whether the alliance is an epiphenomenon of intake characteristics and/or treatment processes occurring over the course of treatment. This meta-analysis aimed to synthesize the evidence on this issue. We identified 125 effect sizes in 60 independent samples (6,061 participants) of studies that reported alliance-outcome correlations as well as parallel intake or process characteristics. We examined the impact of these potential confounds on the alliance-outcome correlations. We meta-analyzed the studies estimates by computing omnibus effects models as well as multivariate models. We identified 3 variable types that were used to adjust the alliance-outcome correlations: (a) intake characteristics (k = 35); (b) simultaneous processes, such as adherence or competence (k = 13); and (c) both intake and simultaneous processes (k = 24). We found moderate alliance-outcome correlations with or without adjustments for intake and simultaneous processes (range from r = .23 to r = .31). Our results provide robust empirical evidence for the assertion that the alliance-outcome association is an independent process-based factor. Findings suggest that alliance is positively related to outcome above and beyond the studied patient intake characteristics and treatment processes.