Objective: Previous studies have shown that feedback-informed treatment can improve outcomes of psychological treatments. This randomized controlled effectiveness trial evaluated the effect of progress feedback on treatment duration, symptom reduction, and dropout in individual cognitive behavioral therapies (CBTs). A control condition where CBT was combined with low-intensive monitoring of progress was compared to an experimental condition where CBT was combined with a high-intensive form of feedback. Method: Data of 368 outpatients (57.9% female, mean age 41.4 years, SD = 12.2) in secondary care were analyzed using multilevel analyses. Treatment duration was assessed with the number of sessions clients received. Symptom reduction was measured with the Symptom Checklist Revised. Possible moderators of the effect of intensive progress feedback on outcome were explored. Results: Clients achieved the same amount of symptom reduction in significantly fewer sessions in the high-intensive feedback condition. Additionally, dropout was significantly lower in the high-intensive feedback condition. Post hoc analyses assessing clients’ diagnoses as a possible moderator showed that clients with personality disorders (mainly Cluster C) achieved more symptom reduction in fewer sessions when high-intensity feedback was provided. Also, a high degree of implementation within the experimental condition was associated with fewer treatment sessions. Conclusion: In sum, the use of high-intensive client feedback reduced treatment duration and reduced dropout of CBT. Thus, feedback-informed CBTs seem to be a promising adaptation of conventional CBT.

Although studies have shown that client feedback can improve treatment outcome, little is known about which factors might possibly moderate the effects of such feedback. The present study investigated potential therapist variables that might influence whether frequent client feedback is effective, including the Big Five personality traits, internal/external feedback propensity and self‐efficacy. Data from two previous studies, a quasi‐experimental study and a randomized controlled trial, were combined. The sample consisted of 38 therapists and 843 clients (55.4% females, mean age = 42.05 years, SD = 11.75) from an outpatient mental health institution. The control condition consisted of cognitive‐behavioural therapies combined with low frequency monitoring of clients' symptoms. In the experimental condition, high‐intensity (i.e., frequent) client feedback as an add‐on to treatment as usual was provided. Outcomes were measured as adjusted post‐treatment symptom severity on the Symptom Checklist‐90 and drop out from treatment. The final model of the multilevel analyses showed that therapists with higher levels of self‐efficacy had poorer treatment outcomes, but when high‐intensity client feedback was provided, their effectiveness improved. Furthermore, higher self‐efficacy was associated with a higher estimation of therapists' own effectiveness, but therapists' self‐assessment of effectiveness was not correlated with their actual effectiveness. The results of this study might indicate that therapists with high levels of self‐efficacy benefit from client feedback because it can correct their biases. However, for therapists with low self‐efficacy, client feedback might be less beneficial, possibly because it can make them more insecure. These hypotheses need to be investigated in future research.