Systematic review of randomized controlled trials of nonpharmacological interventions for fibromyalgia

Objective: Little is known of the effectiveness of nonpharmacological interventions for fibromyalgia syndrome (FMS). The authors therefore carried out a systematic review from 1980 to May 2000 of randomized controlled trials (RCTs) of nonpharmacological interventions for FMS. Method: A search of computerized databases was supplemented by hand searching of bibliographies of key publications. The methodological quality of studies included in the review was evaluated independently by two researchers according to a set of formal criteria. Discrepancies in scoring were resolved through discussion. Results: The review yielded 25 RCTs, and the main categories of interventions tested in the studies were exercise therapy, educational intervention, relaxation therapy, cognitive-behavioral therapy, acupuncture, and forms of hydrotherapy. Methodological quality of studies was fairly low (mean score = 49.5/100). Most studies had small samples (median n for individual treatment groups after randomization = 20), and the mean power of the studies to detect a medium effect (d greater than or equal to 0.5) was 0.36. Sixteen studies had blinded outcome assessment, but patients were blinded in only 6 studies. The median longest follow-up was 16 weeks. Statistically significant between-group differences on at least one outcome variable were reported in 17 of the 24 studies. Conclusions: The varying combinations of interventions studied in the RCTs and the wide range of outcome measures used make it hard to form conclusions across studies. Strong evidence did not emerge in respect to any single intervention, though preliminary support of moderate strength existed for aerobic exercise. There is a need for larger, more methodologically rigorous RCTs in this area.