Reproducibility of the Six-Minute Walk Test in Children and Youth with Juvenile Idiopathic Arthritis.

OBJECTIVE: While the six-minute walk test (6MWT) is increasingly being used in research to evaluate functional exercise capacity of children with juvenile idiopathic arthritis (JIA), psychometric properties with this population have not been well evaluated. The objective of this study was to evaluate reproducibility (agreement and test re-test reliability) and to determine standard error of measurement and smallest detectable difference in children and youth with juvenile idiopathic arthritis.

METHODS: Participants (n=22, x - age =13.1±1.1 years, 63.6% females) completed a 6MWT as part of their routine clinical assessment and repeated it in the same clinical setting with the same rater ( x - = 8 ± 1.2 days later).

RESULTS: ICC (95% CI) was 0.86 (0.66-0.94), standard error of measurement and smallest detectable difference were 23.5 and 65.1 meters, respectively.

CONCLUSION: The results provide evidence of good-excellent reproducibility of the 6MWT with children and youth with JIA and support the use of the 6MWT as a measure of exercise capacity in clinical practice and research.