Pool exercise for patients with fibromyalgia or chronic widespread pain: a randomized controlled trial and subgroup analyses.

OBJECTIVE To evaluate the effects of pool exercise in patients with fibromyalgia and chronic widespread pain and to determine characteristics influencing the effects of treatment. METHODS A total of 134 women with fibromyalgia and 32 with chronic widespread pain were randomized to a 20-session pool exercise and a 6-session education programme or to a control group undertaking the same education programme. The primary outcomes were the Fibromyalgia Impact Questionnaire (FIQ) total score and the 6-minute walk test (6MWT). FIQ Pain and other health variables were included. RESULTS The FIQ total (p = 0.04) improved in the intervention group, with an effect size of 0.32. Patients who had participated in at least 60% of the exercise sessions improved in the FIQ total (effect size 0.44), the 6MWT (effect size 0.43) and FIQ Pain (effect size 0.69) compared with controls (p < 0.05). Long-term follow-up revealed lasting, but small, improvement (effect size < 0.29) in the 6MWT among the active participants (p < 0.05). Analyses within the subgroups showed that patients with milder stress, pain or depression improved most by treatment on the FIQ total (effect size > 0.50, p < 0.05) compared with controls. CONCLUSION The exercise-education programme showed significant, but small, improvement in health status in patients with fibromyalgia and chronic widespread pain, compared with education only. Patients with milder symptoms improved most with this treatment.