Demonstrating Functional Analytic Psychotherapy as an Independent Variable in Efficacy Research: A New Measure of Treatment Fidelity

Field: Psychology (Social Sciences)

Functional Analytic Psychotherapy (FAP) is a contextual behavior therapy that takes an in session, in vivo focus to improve client outcomes. This in vivo (IV) focus is distinctive of FAP and involves the therapist utilization of contingencies in session to decrease problematic response classes and increase more adaptive response classes (i.e., a differential reinforcement procedure). This contingent responding is proposed to be FAP’s mechanism of action leading to client change. FAP efficacy research mainly consists of small n single-case studies or group designs combing FAP with another CBT intervention. Maitland & Gaynor (2012) offered recommendations for increasing FAP efficacy research, including the development of a reliable measure to determine whether a therapist implemented the distinguishing features of FAP. Maitland and Gaynor (2016) developed a 10-item fidelity measure, called the FAP Adherence Form (FAP-AF), to assess for aspects of FAP across 5 items and distinguish it from supportive listening (SL) assessed over 4 items. The measure was used in two FAP outcome studies (Maitland & Gaynor, 2016; Maitland et al., 2016) and it distinguished FAP from SL sessions, suggesting potential utility in distinguishing FAP as an independent variable. The present study, using the data from Maitland et al. (2016), provides a more comprehensive analysis by assessing reliability between 3 independent coders, correlations with another FAP-specific fidelity metric, and investigating for possible mediator relationships between the FAP-AF and outcomes. The alternative fidelity technique used for comparison was developed by Kanter, Schildcrout, & Kohlenberg (2005) and involves coding each turn of speech as in vivo (talk directed at the therapy process, therapy relationship, or in the moment interactions) or not. If the FAP-AF and in vivo counts capture the presence or absence of FAP elements, they should be reliable across coders. Likewise, the in vivo turns count should correlate with the 5-item FAP scale on the FAP-AF, but neither should correlate with the 4-item SL scale, distinguishing FAP from SL. Finally, if the FAP-AF acts as a proxy for FAP’s mechanism of action it should mediate outcomes. Results demonstrated mostly excellent reliability between coders. Exact agreement on the FAP scale items ranged from 71% to 95%. Inter-method correlations indicated strong positive relationships between and within coders on the adherence metrics. Furthermore, the FAP scale and IV turns count significantly differed in FAP sessions compared to SL sessions suggesting the measures distinguished the presence of FAP from its absence. As such, the FAP scale may be useful in documenting FAP as an independent variable providing a reliable but less intensive method for assessing treatment fidelity. However, no adherence metrics replicated Maitland et al. (2016) in serving as a statistical mediator of outcomes. The individual level relationships observed between adherence and symptom outcomes suggested significant variability and an absence of an overall dose-response relationship. The lack of a clear dose-response relationship could indicate a limitation of the adherence measures used. Not all FAP interactions are equal in their potency an effect which is hard to quantify. Implications, future directions, and limitations are discussed.