The purpose of this study was to review randomized controlled trials of the effects of treatment in spas, thereby clarifying therapeutic effects of these treatments on individual diseases, and its healthpromoting effects.
A review of the PubMed database for articles that fulfilled the following eligible criteria identified the studies that were chosen for this review. Key words were “randomized controlled trial” and “spa” or “balneotherapy”. Articles were published after 1990, and written in English. No criteria were set up concerning the number of subjects, the observation period, or the kind of disease studied. The quality of individual articles was evaluated on a 13-point modified PEDro scale that was constructed by adding three terms, representing the number of subjects, the observation period, and quellencharakter to the 10-point PEDro scale.
A total of 18 articles were chosen. Since two of them were essentially identical in content, these two articles were counted as one. As a result, a total of 17 articles were reviewed. Seven studies were conducted in France, 3 in Germany, 3 in Israel, 2 in the Netherlands, and 1 each in Italy and in Japan. Diseases studied in these articles were mostly disorders of the locomotorium, with pain as a main symptom; rheumatism in 6 articles, osteoarthritis in 4, lumbago in 3, and Parkinson's disease, varicosis, psoriasis, and health-promotion in one each. The mean score on the 13-point modified PEDro scale was 7.5 (SD, 2.3), with a minimum score of 2 points and a maximum score of 12 points.
The method of intervention in the spa varied widely from study to study. In addition to balneotherapy, exercise therapy, mud pack treatment, and douche massage were employed in numerous studies. Besides the intensity of pain and the amount of anodynes consumed by patients, emotional effects, QOL, physical working capacity, and even decreases in medical expenses were monitored as indicators for evaluation of the effect of the treatments in some studies. Improvements in the indicators were always more marked in balneotherapy intervention groups than in control groups, irrespective of the diseases studied. The improvements persisted for relatively long periods. In particular, a review of the high quality articles that reported effects of balneotherapy on patients with rheumatism, osteoarthritis, or lumbago showed that effects of intervention provided only once could be expected to persist for six months. With regard to the effect of quellencharakter on diseases, no definitive conclusion was obtained. On the basis of these results, we devised a “3-layer model of evidence to be accumulated in balneotherapy”