Exposure and cognitive-behavioural therapy for chronic back pain: An RCT on treatment processes

Background To improve treatment outcomes, it is essential to understand the processes involved in therapeutic change. The aim of this study was to investigate the processes involved in treatment of individuals with chronic lower back pain (CLBP) and high fear-avoidance. Graded in vivo exposure (Exposure), a specific treatment, and cognitive-behavioural therapy (CBT), a general treatment, were compared. Methods Our study used data from a three-arm randomized controlled trial. The sample comprised 61 CLBP patients (pain duration >3 months; sufficient level of fear-avoidance). Assessments of session-by-session processes were done weekly for a maximum 14 weeks. The primary outcome, functional disability, was assessed at pre-treatment, post-treatment and 6-months follow-up. First, two-level models were used to test for treatment-related similarities and differences in the changes in session-by-session measures (i.e., common and unique treatment processes respectively). Second, we analysed treatment processes as predictors of treatment outcome. Results Contrary to our expectations, we found no evidence of unique treatment processes. Our results indicate that Exposure and CBT share some treatment processes. Specifically, patients reported a reduction in fear of movement and improvements in their ability to relax, to distract themselves, to manage their pain, to confront feared movements, to be active and to enjoy things despite their pain. Changes in fear of movement, relaxation, distraction, confrontation, activity and pain-related self-efficacy were also related to disability reduction. Conclusions Despite conceptual differences, Exposure and CBT may share common treatment processes. Future research needs to address, however, whether these processes need to be targeted directly or can be supported indirectly. Significance: We identified several treatment processes (e.g., reduction of fear of movement, enhancement of self-efficacy), which were associated with disability reduction during the management of chronic pain and fear-avoidance. These processes appeared to be equally important for Exposure and CBT. Practitioners should optimize these processes to improve their patients' functioning.