The efficacy of balneotherapy, mud therapy and spa therapy in patients with osteoarthritis: an overview of reviews

Osteoarthritis is a degenerative disease considered a leading cause of functional disability. Its treatment is based on a combination of pharmacological and non-pharmacological interventions, but the role of these latter is still debated. This overview of systematic reviews aimed at evaluating the short-term efficacy of different thermal modalities in patients with osteoarthritis. We searched PubMed, Scopus, CINHAL, Web of Science, ProQuest and the Cochrane Database of Systematic Reviews from inception until October 2020, with no language restrictions. We selected the following outcomes a priori: pain, stiffness and quality of life. Seventeen systematic reviews containing 27 unique relevant studies were included. The quality of the reviews ranged from low to critically low. Substantial variations in terms of interventions studied, comparison groups, population, outcomes and follow-up between the included SRs were found. From a re-analysis of primary data, emerged that balneotherapy was effective in reducing pain and improving stiffness and quality of life, mud therapy significantly reduced pain and stiffness, and spa therapy showed pain relief. However, the evidence supporting the efficacy of different thermal modalities could be seriously flawed due to methodological quality and sample size, to the presence of important treatment variations, and to the high level of heterogeneity and the absence of a double-blind design. There is some encouraging evidence that deserves clinicians' consideration, suggesting that thermal modalities are effective on a short-term basis for treating patients with AO.