Change in Pain-Related Anxiety Mediates the Effects of Psychophysiologic Symptom Relief Therapy (PSRT) on Pain Disability for Chronic Back Pain: Secondary Results from a Randomized Controlled Trial.

Purpose: Widely used therapeutic approaches, such as cognitive-behavioral and mindfulness-based therapies, can improve pain and functioning in people with chronic back pain, but the magnitude and duration of their effects are limited. Our team developed a novel 12-week program, psychophysiologic symptom relief therapy (PSRT), to substantially reduce or eliminate pain and disability. This study examined whether PSRT helped more patients achieve large-magnitude (≥30%, ≥50%, ≥75%) reductions in back pain-related disability compared to mindfulness-based stress reduction (MBSR) and usual care (UC), and if the beneficial effects of PSRT were explained by reductions in pain-related anxiety following treatment. Patients and Methods: Data from a three-armed randomized controlled trial were used (N=35 adults with chronic back pain). Change scores (baseline to 4-, 8-, 13-, and 26-weeks post-enrollment) were computed for back pain disability (RDQ) and pain-related anxiety (PASS-20). Fisher's exact tests and mediation analyses were conducted. Results: Compared to MBSR and UC, PSRT helped significantly more patients achieve ≥75% reductions in back pain disability at all timepoints and in pain anxiety at all timepoints except 13-weeks. Change in pain anxiety significantly mediated the relationship between treatment group and change in back pain disability from baseline to 26-weeks. Conclusion: PSRT helped more patients achieve substantial reductions in disability than an established treatment (MBSR) and usual care. Findings indicate reduced pain anxiety may be a mechanism by which PSRT confers long-term benefits on disability. Importantly, this work aims to move the field toward more precise and effective treatment for chronic back pain.