Therapeutic benefit of balneotherapy and hydrotherapy in the management of fibromyalgia syndrome: a qualitative systematic review and meta-analysis of randomized controlled trials

Introduction: In 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). Methods: A 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. Results: Meta-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. Conclusions: High-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.