Does structured, psychometrically based feedback discussion cause improvements of the therapeutic alliance? A single-case experimental study

Routine outcome monitoring and feedback (ROM) systems have been established to enhance therapeutic outcomes, prevent drop-outs and facilitate data-driven personalization in psychotherapy. However, the underlying mechanisms of ROM systems remain unknown, although the therapeutic alliance has been discussed as a potential mechanism. In this pre-registered (https://osf.io/jkmct) single case experimental design study with multiple (3) baselines and <i>N</i> = 34 outpatients in routine care, a potential causal effect of the structured discussion of feedback on the therapeutic alliance over the first 20 sessions is investigated. The single case effects were aggregated using a random effects meta-analysis to estimate the group-level effect and its heterogeneity. As potential moderators, baseline impairment and level of personality functioning were tested. The meta-analysis resulted in a significant effect size of Ruscio's <i>A</i> = 0.92 with a 95% CI [0.88, 0.95] (<i>p</i> < .001) and Hedges' <i>g</i> = 1.33 with a 95% CI [1.04, 1.62] (<i>p</i> < .001). The potential moderators were not significant. These results establish causality between the structured feedback discussions and the improvement of the therapeutic alliance with large, robust effect sizes regardless of case complexity and open up the possibility of using ROM systems as a specific intervention to increase the therapeutic alliance.