The primary aim of this study was to develop a reliable and valid measure of therapist adherence and competence in delivering a new mindfulness-based treatment for substance use disorders. Results demonstrated high interrater reliability for all treatment adherence and competence subscales of the MBRP-AC, which suggests that it is possible for students at various levels of psychology training to be trained to code MBRP sessions effectively and reliably. This finding is encouraging and would reduce the high cost and time expenditure typically associated with expert-level adherence and competence ratings. Another encouraging finding was the high level of internal consistency for therapist style and competence ratings. This finding indicates that the competence subscales are consistently tapping into key MBRP constructs.
Concerning the validity of the MBRP-AC, competence of overall treatment delivery and use of Inquiry and Use of Key Questions appear to be significantly related to client ratings of working alliance, suggesting that therapists’ skillful facilitation and exploration of clients’ experiences may foster a positive therapeutic relationship with clients. Additionally, the relationship between overall therapist adherence and changes in client mindfulness over the eight weeks of the course suggests that close adherence to the MBRP protocol may facilitate increases in clients’ levels of mindfulness. Given that most exercises and practices in MBRP are designed to increase mindful awareness (Bowen at al., in press
), this association is not surprising. Indeed, it suggests that facilitation of these practices is contributing to a primary goal of the intervention. Somewhat surprising is the lack of association between therapist competence and client mindfulness. It is possible that the current MBRP-AC competence subscales do not fully reflect the key factors of competence necessary for optimal delivery of MBRP. Future studies are necessary to determine whether this finding is limited to the current sample.
Once reliability and validity of the MBRP-AC was established, we used this measure to assess the adherence and competence attained in the first RCT of MBRP. Although the MBRP therapists did not reach the hypothesized 100% adherence to the MBRP components, findings suggested relatively high levels of adherence for an initial feasibility and efficacy trial (90%). The Use of Key Concepts subscale of the Adherence section showed 100% adherence to the key concepts of MBRP, which were discussed in all groups and in all sessions. On a scale of 1 (low) to 5 (high), mean ratings of both the Therapist Style/Approach subscale and the overall performance section were close to a four. Taken together, these descriptive findings suggest sufficient reliability and validity of the MBRP-AC to assess therapist treatment delivery. Further, ratings on the MBRP-AC suggest therapists in the recent RCT adhered to protocol, discussed key concepts in each session, and demonstrated the intended style and overall competence intended in the treatment.
Despite these encouraging preliminary findings, there are also several limitations that deserve mention. First, the study did not assess treatment discriminability, or the extent to which the scale can distinguish between MBRP and other types of interventions with which it shares common elements (e.g., MBCT and RP). According to Waltz and colleagues (1993)
a key element of measure adherence is the examination of unique and common elements of different treatments. Thus, an important task for future research comparing MBRP to other treatments is to build in further components that will assess prescribed components for MBRP and other, related treatments to optimally assess treatment discriminability. A second limitation of the MBRP-AC is that it only assesses prescribed therapist behaviors and not those that are proscribed by the MBRP treatment manual. Although we asked raters to make a note of therapist behaviors that appeared contrary to the treatment, these were not quantified for the purposes of the current study. Thus, consistent with the recommendations of Waltz et al. (1993)
, future research would benefit from an added focus on enumerating therapist behaviors that are inconsistent with or violate the treatment guidelines for MBRP.
Overall, these limitations indicate a need to further refine and develop the current measure. However, given that MBRP is one of the first mindfulness-based interventions to address relapse related to substance use disorders, the development and assessment of the MBRP-AC is an important step to assessing and enhancing MBRP treatment integrity for future trials and clinical applications.