Ten RCTs were included in the review (n=446, range 24 to 80). Three studies had a moderate quality score and seven had a low quality score. None of the included studies undertook an intention-to-treat analysis or performed an adequate allocation concealment. Due to the small number of studies it was not possible to assess publication bias, although fail-safe N suggested that publication bias was absent.
By the end of therapy, hydrotherapy resulted in a significant reduction of pain (SMD -0.78, 95% CI -1.42 to -0.13; nine study arms) and improved HRQoL (SMD -1.67, 95% CI -2.91 to -0.43; four studies). At the latest follow-up (median 14 weeks), there was a significant reduction of pain (SMD -1.27, 95% CI -2.15 to -0.38; four studies) and improved HRQoL (SMD -1.16, 95% CI -1.96 to -0.36; four studies). Significant heterogeneity was present for all comparisons (I2>83%).
Subgroup analyses were presented and sensitivity analyses did not alter the findings.