Treatment Outcomes and Mechanisms for an ACT‐Based 10‐Week Interdisciplinary Chronic Pain Rehabilitation Program

BACKGROUND: Interdisciplinary pain rehabilitation programs are an evidence-based biopsychosocial treatment approach for chronic pain. The purpose of the current study is to assess outcomes for a 10-week interdisciplinary, acceptance and commitment therapy (ACT)-based, outpatient treatment model and to evaluate the relationship between psychological process variables (ie, pain catastrophizing, pain acceptance, pain self-efficacy) and treatment outcomes. METHODS: 137 adults with chronic pain completed an interdisciplinary pain rehabilitation program. Measures of pain, pain interference, health-related quality of life, anxiety, depressed mood, insomnia, pain catastrophizing, pain acceptance, and pain self-efficacy were completed at admission and discharge. Data were also collected on demographic and clinical variables, including opioid use. RESULTS: Results indicated significant changes in all measures at program discharge compared to admission. Opioid doses were also reduced. Results of within-subjects meditational analyses indicated that pain catastrophizing accounted for a significant portion of the treatment effect for pain severity, pain interference, and depressed mood. Pain acceptance was a mediator for change in depressed mood, whereas pain self-efficacy was a mediator for pain interference outcomes. CONCLUSIONS: This study supports a 10-week, ACT-based treatment model for interdisciplinary chronic pain rehabilitation. In addition, pain catastrophizing, pain acceptance, and pain self-efficacy were each found to be mechanisms by which individuals achieve successful treatment outcomes. This research provides further support for interdisciplinary rehabilitation approaches for chronic pain.