Efficacy of hydrotherapy in fibromyalgia syndrome--a meta-analysis of randomized controlled clinical trials.

OBJECTIVE To systematically review the efficacy of hydrotherapy in FM syndrome (FMS). METHODS We screened MEDLINE, PsychInfo, EMBASE, CAMBASE and CENTRAL (through December 2008) and the reference sections of original studies and systematic reviews on hydrotherapy in FMS. Randomized controlled trials (RCTs) on the treatment of FMS with hydrotherapy (spa-, balneo- and thalassotherapy, hydrotherapy and packing and compresses) were analysed. Methodological quality was assessed by the van Tulder score. Effects were summarized using standardized mean differences (SMDs). RESULTS Ten out of 13 RCTs with 446 subjects, with a median sample size of 41 (range 24-80) and a median treatment time of 240 (range 200-300) min, were included into the meta-analysis. Only three studies had a moderate quality score. There was moderate evidence for reduction of pain (SMD -0.78; 95% CI -1.42, -0.13; P < 0.0001) and improved health-related quality of life (HRQOL) (SMD -1.67; 95% CI -2.91, -0.43; P = 0.008) at the end of therapy. There was moderate evidence that the reduction of pain (SMD -1.27; 95% CI -2.15, -0.38; P = 0.005) and improvement of HRQOL (SMD -1.16; 95% CI -1.96, -0.36; P = 0.005) could be maintained at follow-up (median 14 weeks). CONCLUSIONS There is moderate evidence that hydrotherapy has short-term beneficial effects on pain and HRQOL in FMS patients. There is a risk to over-estimate the effects of hydrotherapy due to methodological weaknesses of the studies and to small trials included in meta-analysis.