IntroductionIn the present systematic review and meta-analysis, we assessed the effectiveness of different forms of balneotherapy (BT) and hydrotherapy (HT) in the management of fibromyalgia syndrome (FMS).MethodsA systematic literature search was conducted through April 2013 (Medline via Pubmed, Cochrane Central Register of Controlled Trials, EMBASE, and CAMBASE). Standardized mean differences (SMDs) and 95% confidence intervals (CIs) were calculated using a random-effects model.ResultsMeta-analysis showed moderate-to-strong evidence for a small reduction in pain (SMD −0.42; 95% CI [−0.61, −0.24]; P < 0.00001; I2 = 0%) with regard to HT (8 studies, 462 participants; 3 low-risk studies, 223 participants), and moderate-to-strong evidence for a small improvement in health-related quality of life (HRQOL; 7 studies, 398 participants; 3 low-risk studies, 223 participants) at the end of treatment (SMD −0.40; 95% CI [−0.62, −0.18]; P = 0.0004; I2 = 15%). No effect was seen at the end of treatment for depressive symptoms and tender point count (TPC).BT in mineral/thermal water (5 studies, 177 participants; 3 high-risk and 2 unclear risk studies) showed moderate evidence for a medium-to-large size reduction in pain and TPC at the end of treatment: SMD −0.84; 95% CI [−1.36, −0.31]; P = 0.002; I2 = 63% and SMD −0.83; 95% CI [−1.42, −0.24]; P = 0.006; I2 = 71%. After sensitivity analysis, and excluding one study, the effect size for pain decreased: SMD −0.58; 95% CI [−0.91, −0.26], P = 0.0004; I2 = 0. Moderate evidence is given for a medium improvement of HRQOL (SMD −0.78; 95% CI [−1.13, −0.43]; P < 0.0001; I2 = 0%). A significant effect on depressive symptoms was not found. The improvements for pain could be maintained at follow-up with smaller effects.ConclusionsHigh-quality studies with larger sample sizes are needed to confirm the therapeutic benefit of BT and HT, with focus on long-term results and maintenance of the beneficial effects.