Twenty-nine RCTs (including one cross-over trial) were included and 25 (n=1,720, range 23 to 224) of these were included in the synthesis. All except two of the included studies scored 3 or more on the Oxford Quality Scale (most scored 3). Oxford Pain Validity Scale scores ranged from 7 to 15. Length of follow-up ranged from two weeks to one year.
Pain: There was a statistically significant improvement in pain in 17 of the 25 trials in the balneotherapy group compared to control. There was no statistically significant difference between groups in eight trials.
Morning stiffness: There was a statistically significant improvement in the balneotherapy group compared to control in morning stiffness for one study. There was no statistically significant difference in the other seven studies that assessed this outcome.
Number of tender points and Fibromyalgia Impact Questionnaire: There was a statistically significant improvement with balneotherapy compared to control in three of the five studies that assessed these outcomes.
Analgesic consumption: There was a statistically significant improvement with balneotherapy compared to control in two of the five studies.
Quality of life: There was a statistically significant improvement with balneotherapy compared to control in all four studies.