Background/Purpose: Identifying the factors associated with response to nonpharmacological therapies in patients with fibromyalgia will help personalize treatments and provide information to improve the design and interpretation of future research. We used results from a large comparative effectiveness trial of Tai Chi versus aerobic exercise to investigate baseline characteristics associated with clinical response at 24 weeks in patients with fibromyalgia.

Methods: We analyzed data from a randomized trial which enrolled 226 adults with fibromyalgia as defined by the ACR 1990 and 2010 criteria. Participants were assigned to aerobic exercise (2x/week for 24 weeks) or one of four Tai Chi interventions (1x or 2x/week for 12 or 24 weeks) and followed for 52 weeks. Results from the trial showed that all treatment groups demonstrated improvement in revised fibromyalgia impact questionnaire (FIQR) scores, but the combined Tai Chi groups improved significantly more in FIQR score at 24 weeks than the aerobic exercise group. Although a minimal clinically important difference (MCID) in response has not yet been determined for the FIQR, FIQR scores correlate closely with scores of the original fibromyalgia impact questionnaire (FIQ) (r=0.88, P< 0.001). Based on the established MCID of the FIQ, we estimated the MCID of the FIQR to be 14% or 8.1 units on a 0-100 scale. We performed a stepwise multivariable analysis to investigate baseline variables associated with positive response (our criteria for entry was univariate p< 0.10). Baseline variables included demographics (sex, age, race, education, and whether they live alone) and clinical measurements (BMI, duration of body pain, pain index, symptom severity, FIQR, global assessment, depression, anxiety, self-efficacy, coping skills, sleep quality, 6-minute walk test, physical and mental quality-of-life components of the Short-Form 36, analgesic use, comorbidities, and outcome expectations).

Results: Mean age of the 181 participants with complete data at 24 weeks was 52.3 years, 91.7% were female, average BMI was 30.1 kg/m2, and average duration of body pain was 12.4 years. Mean FIQR at baseline was 55.5. There were 108 participants (60%) who responded to either treatment. When the six variables which were significant (p< 0.10) in the univariate analyses were included in the multivariate analysis, only FIQR remained significant (Table). Having a higher FIQR score or greater impact of symptoms was significantly associated with clinically meaningful improvement at 24 weeks (p = 0.01). Response did not significantly differ by treatment.

Conclusion: Individuals with fibromyalgia who had more severe symptoms seem to experience greater clinical improvement from nonpharmacological interventions such as Tai Chi or aerobic exercise than those who are less impacted by their condition. More studies are warranted to confirm whether other clinical variables may be associated with positive response. These findings will aid in improving the design of future trials for patients with fibromyalgia.

ACR_FMEx_Responder_Table

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/a-positive-response-to-nonpharmacological-therapies-in-patients-with-fibromyalgia/