Effectiveness of Radon Spa Therapy in Multimodal Rehabilitative Treatment of Rheumatoid Arthritis

To replicate former observed beneficial effects of Radon (plus CO2) baths on RA in contrast to artificial CO2 baths and to investigate its long-term effectiveness and impact on drug consumption.

Methods: Randomised double-blinded trial with 2 randomised balanced groups enrolling 134 patients of an in-patient rehabilitative programme (a 3rd non-randomised group of 73 consecutive patients is not reported here). Outcomes were limitations in occupational context/ daily living, pain, functional capacity, morning stiffness and medication measured before start, after end of treatment, and quarterly in the year thereafter. Repeated-measures analysis of covariance (RM-ANCOVA) of intent-to treat population was performed to investigate treatment effects. Hierarchically ordered hypotheses ensured adherence of the nominal significance level and allowed examining of long-term effects. Starting with all measures until 6 months' follow-up, significant main effects for group allocation (GME) or significant group x course-interactions (GxC) were regarded essential to add the next follow-up for analysis.

Results: Radon treatment resulted in significantly lower limitations of daily living over at least 9 months whereas reference patients returned to baseline level after 6 months already (RM-ANCOVA until 6 months: pGME=.15, pGxC=.016/ 9 months: pGME=.11, pGxC=.025/ 12 months: pGME=.17, pGxC=.033). Furthermore, consumption of steroids and NSAID was remarkably reduced in the Radon group (RM-ANCOVA until 12 months: for steroids pGME=.064, interaction pGxC=.025, maximum difference after 12 months; for NSAID pGME=.035, interaction pGxC=.008, maximum difference after 9 months).

Conclusion: Results suggest beneficial long-term effects of Radon baths as adjunct to a multimodal rehabilitative treatment of RA.