(PS9-90) Patient-Perceived Treatment Credibility as a Moderator of the Association between Therapist Adherence and Patient Outcome in CBT

Abstract Text:

Background: Although it has long been assumed that greater therapist adherence to evidence-based treatment protocols should be associated with better patient outcomes, meta-analyses have failed to support this notion (Power et al., 2022). In fact, some studies have indicated that higher adherence levels can be detrimental in certain contexts, such as moments of patient-therapist disagreement (e.g., Aviram et al., 2016). However, less is known about the contexts and patients for whom greater adherence may be beneficial. In this vein, it is plausible that therapist adherence would be especially helpful for patients who perceive a given treatment to be highly credible (i.e., logical, suitable, and effective) once hearing about its rationale. The present study tested this hypothesis in the context of cognitive-behavioral therapy (CBT) for generalized anxiety disorder (GAD).

Method: Data are derived from one arm of randomized clinical trial in which 54 adult patients received 15 sessions of CBT for severe GAD (Westra et al., 2016). The sample was, on average, 34.4 years old (SD = 12.0), predominantly female (92.6%, n = 52), and White (77.8%, n = 42). After session 1, patients reported perceived treatment credibility via the relevant subscale of the Credibility/Expectancy Questionnaire (Devilly & Borkovec, 2000). Trained observers rated therapist treatment adherence at an early, middle, and late session using the Cognitive Therapy Rating Scale (CTRS; Young & Beck, 1980). As the outcome variable, patients rated their worry severity at pre- and posttreatment via the Penn State Worry Questionnaire (PSWQ; Meyer et al., 1990).

Results: Linear regression analyses indicated there was no significant interactive effect of patients’ early treatment credibility perception and average therapists’ treatment adherence on posttreatment worry (B = 4.12, p = 0.52). There was also no main effect of average adherence on outcome (B = 0.58, p = .99), though higher credibility predicted lower posttreatment worry (B = -8.00, p = 0.007).

Discussion: Counter to our hypothesis, the results did not reveal a condition under which therapist CBT adherence predicted better patient outcomes. As this was a novel research focus, future research is needed to corroborate or challenge this null finding. Notably, the findings did replicate existing research on the patient-perceived credibility-outcome link; namely, the more a patient viewed the treatment as credible, the more likely they were to benefit from it. Thus, therapists may wish to engage in strategies for promoting patient credibility perceptions if a given treatment, even if they do not adhere strictly to a manualized version of said treatment.