The association between physical intervention use and treatment outcomes in patients participating in an online and psychologically informed pain management program.

Background: The availability of multidisciplinary care for the management of chronic pain is uncommon outside specialist clinics. The current study aims to determine the physical intervention use of patients participating in an online psychological pain management program and whether exposure to physical interventions in these patients alters treatment outcomes compared to patients who do not access physical interventions.

Methods: Data were obtained from two previously published randomised control trials of an online psychological pain management program. Physical intervention exposure (category: None, 1-3, 4+ sessions) was assessed at baseline, post-treatment and at 3-month follow-up. Primary outcomes included depression, anxiety, pain intensity and pain-related disability. Generalised estimating equation models were used to compare treatment outcomes between those with different physical intervention frequencies and period of exposure. We assessed whether changes in primary outcomes differed (moderated) depending on the period and category of physical intervention exposure.

Results: N = 1,074 patients completed the baseline questionnaire across both RCTs, of whom 470 (44%) reported physical intervention use at baseline, 383 (38%) at post-treatment and 363 (42%) at 3-month follow-up. On average, there were moderate-large reductions from baseline to post-treatment with respect to all outcomes (Cohen's d = 0.36-0.82). In all outcomes, the interaction of time by physical intervention exposure was statistically non-significant.

Conclusion: A substantial proportion of patients who participated in a psychologically informed pain management program were establishing, continuing, or stopping additional physical interventions. The frequency and period of exposure to physical interventions did not appear moderate treatment outcomes.