Given the known side effects of opioids and their potential effects on cognition, we sought to evaluate the benefits of motivational interviewing (MI) to promote physical activity on 2 subsets of participants with fibromyalgia (FM): nonusers and users of opioids.
This was a secondary data analysis of a 36-week randomized controlled trial to assess the efficacy of MI to promote physical activity among participants with FM. Participants were randomized to 1 of 2 treatment arms: 6 phone-based MI sessions (n = 107) or 6 sessions of FM self-management instructions [attention control (AC), n = 109]. The primary outcomes were changes in physical function (Medical Outcomes Study Short Form-36), pain severity (Brief Pain Inventory), global FM symptom severity (Fibromyalgia Impact Questionnaire), and the amount of light to moderate physical activity (LMPA) from baseline to each followup visit. At study entry, subjects were categorized as opioid nonusers versus users. Repeated measures ANOVA was used to assess treatment effects adjusting for potential confounders.
Of the 216 participants, 145 (67%) were nonusers and 71 (33%) were opioid users. Among nonusers, MI was associated with improved physical function, reduced pain severity, and global FM severity, and increased LMPA at 6-month followup. Among opioid users, there were no significant differences in any outcome measures between the MI and AC groups.
Exercise-based MI was associated with sustained clinical benefits 6 months after completion of therapy, but only for those who were not taking opioids.