Associations between treatment adherence-competence-integrity (ACI) and adult psychotherapy outcomes : a systematic review and meta-analysis.

Abstract

Objective: To provide a comprehensive assessment of the association between psychological treatment adherence/competence/integrity (ACI) and clinical outcomes. Method: The review protocol was pre registered (CRD42020193889). Studies that assessed ACI-outcome relationships for adult psychotherapy were searched across three databases (Scopus, PsycINFO, MEDLINE). Random effects meta-analyses were conducted on adherence-outcome, competence-outcome and integrity-outcome relationships. Separate analyses were performed for studies with hierarchical (i.e. patients nested within therapist) versus non-hierarchical study designs. Moderator analyses were performed according to pre defined clinical and methodological features. GRADE assessments rated the quality of each meta analytic comparison. Results: The review identified 62 studies suitable for inclusion (45 adherence outcome, 39 competence-outcome and 7 integrity-outcome effect sizes; N=8,210 across all analyses). No significant adherence-outcome association was found. A small significant positive association was found only in non-hierarchical studies between competence and outcome (r = 0.17, 95% CI [0.07- 0.26], p < 0.001, ~d = .34, GRADE = moderate). Small-to-moderate significant positive associations between integrity and outcome were found for both non-hierarchical (r = 0.15, 95% CI [0.06 – 0.23], p < 0.001, ~d = .30, GRADE = high) and hierarchical study designs (r = 0.23, 95% CI [0.01,0.43], p < 0.044, ~d = .47, GRADE = low). Diagnosis, treatment modality and year of publication significantly moderated the strength of ACI-outcome correlations. Conclusions: Competence and integrity are significantly associated with clinical outcome, with a magnitude comparable to wider common factors. Further research is required to study these process-outcome associations with greater precision in routine-care settings and to understand the role of moderating variables.