Primary Outcome Measures:
- limitations in everyday life and private activities
- limitations in the occupational context (not for pensioners)
- (both self-assessed on 2 100mm-VAS, averaged into 1 criterion if applicable)
Secondary Outcome Measures:
- pain intensity
- pain frequency
- morning stiffness
- functional capacity
- drug consumption (steroids; NSAIDs; DMARDs only descriptively)
Objective: 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.