Overview of Systematic Reviews with Meta-Analysis Based on Randomized Controlled Trials of Balneotherapy and Spa Therapy from 2000 to 2019

Open-access umbrella review surveying all systematic reviews and meta-analyses on balneotherapy and spa therapy published between 2000 and 2019. Published in the International Journal of General Medicine, Kamioka and Nobuoka provide a 20-year synthesis of the field’s highest-quality evidence — reviews of reviews, filtered to meta-analyses based on randomised controlled trials.

The 2000–2019 Window

The choice of this time window is significant: 2000–2019 captures the period when balneotherapy research matured methodologically. Earlier literature relied heavily on observational studies and clinical observations; this review focusses on the period when RCT-based meta-analyses became available. The result is a picture of what the field could demonstrate to modern evidence standards over two decades.

What It Found

Consistent positive findings across systematic reviews for musculoskeletal conditions — knee osteoarthritis and chronic musculoskeletal pain in particular have robust RCT-based meta-analytic support. For dermatological conditions, the evidence is more varied: positive findings for psoriasis and atopic dermatitis appear across reviews, but the methodological quality of included studies is lower, and effect sizes are more heterogeneous. The review identifies specific gaps where evidence needs strengthening — primarily in dermatology and in understanding long-term effects.

Paired with Antonelli 2021

Kamioka 2020 covers 2000–2019; Antonelli 2021 provides updated synthesis including more recent studies. Together they form a continuous systematic view of balneotherapy evidence from the beginning of the modern RCT era. Both are cited when an umbrella-level reference is needed for the overall evidence base.