title: Long-term efficacy of radon spa therapy in rheumatoid arthritis--a randomized, sham-controlled study and follow-up.
abstract: OBJECTIVE
  To quantify the efficacy of a series of baths containing natural radon and carbon dioxide (1.3 kBq/l, 1.6 g carbon dioxide/l on average) versus artificial carbon dioxide baths alone in patients with rheumatoid arthritis.
  
  
  METHODS
  Sixty patients participating in an in-patient rehabilitation programme including a series of 15 baths were randomly assigned to two groups.
  
  
  METHODS
  Pain intensity (100 mm visual analogue scale) and functional restrictions [Keitel functional test, Arthritis Impact Measurement Scales (AIMS questionnaire)] were measured at baseline, after completion of treatment and 3 and 6 months thereafter. To investigate whether the overall value of the outcomes was the same in both groups, the overall mean was analysed by Student's t-test for independent samples.
  
  
  RESULTS
  The two groups showed a similar baseline situation. After completion of treatment, relevant clinical improvements were observed in both groups, with no notable group differences. However, the follow-up revealed sustained effects in the radon arm, and a return to baseline levels in the sham arm. After 6 months, marked between-group differences were found for both end-points (pain intensity: -16.9%, 95% confidence interval -27.6 to -6.2%; AIMS score: 0.57, 95% confidence interval 0.16 to 0.98). The between-group differences were statistically significant for both overall means (pain intensity, P: = 0.04; AIMS, P: = 0.01).
  
  
  CONCLUSIONS
  Marked short-term improvements in both groups at the end of treatment may have masked potential specific therapeutic effects of radon baths. However, after 6 months of follow-up the effects were lasting only in patients of the radon arm. This suggests that this component of the rehabilitative intervention can induce beneficial long-term effects.
authors.affiliation: Balneology and Rehabilitation Sciences Research Institute (FBK), Bad Elster, Maximilians University, Munich, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Franke
authors.forename: L
authors.initials: L
authors.lastname: Reiner
authors.forename: H G
authors.initials: HG
authors.lastname: Pratzel
authors.forename: T
authors.initials: T
authors.lastname: Franke
authors.forename: K L
authors.initials: KL
authors.lastname: Resch
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000503:physiopathology / Q000534:rehabilitation*; D001494:Baths; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000503:physiopathology; D011886:Radon / Q000627:therapeutic use*; D012680:Sensitivity and Specificity; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D011886:Radon