Acceptance and Commitment Therapy with Chronic Pain Patients: Using a Delphi Study to Gather an Expert Consensus on Client Language in Relation to Psychological Flexibility

Introduction: There is increasing research evidence to support the effectiveness of Acceptance and Commitment Therapy (ACT) in treating chronic pain, but relatively little on the hypothesised change processes thought to underlie it. ACT is rooted in a theory of human language and cognition and if an ACT intervention was successful, this should be reflected in a change in the language used by the patient when talking about their experience of pain. However, there is currently no clear understanding regarding the form these changes might take. Aim: The current study aimed to gather a consensus from experts in the fields of chronic pain and ACT regarding client language in relation to psychological flexibility, the key theoretical construct in ACT. The focus was to create a pool of statements thought to typify client language during therapy that reflects psychological in/flexibility and that could inform future outcome and process research. Method: Participants were recruited using a mixture of purposeful and snowball sampling to take part in a Delphi study. The study involved three iterative rounds of data collection and analysis. Quantitative and qualitative data analysis included simple descriptive statistics and thematic analysis respectively. Results: Participants generated 478 statements representing client language reflective of psychological in/flexibility in round one. Participants found it hardest to produce statements in relation to the ‘now as known’ processes. The item pool was reduced/amended on the basis of participant feedback in round two leaving 160 items for round three. A final item pool was obtained in round three using two different consensus cut-offs, and data was gathered on the process. Participants were often split in their decision making regarding statements inconsistent with the target processes, but offered several insights into hypothesised key characteristics of client language before and after successful ACT. Discussion: The results are contextualised within the wider literature. The strengths and limitations of the current study are explored. Finally, areas for future research and the clinical implications of the current study are considered.