Abstract

Objectives: The six-minute walk test (6MWT) is a frequently used indicator of functional exercise capacity. The goals of this study were to compare the six-minute walk performance of three paediatric patient groups with that of healthy peers, to assess differences between published reference values and to investigate which anthropometric characteristics best predict six-minute walk performance.

Methods: Forty-seven children with haemophilia (mean ± SD age 12.5 ± 2.9), forty-four with juvenile idiopathic arthritis (JIA) (mean ± SD age 9.3 ± 2.2) and twenty-two with spina bifida (SB) (mean ± SD age 10.3 ± 3.1) were included. Subjects performed a 6MWT and the distance walked (6MWD) was compared with published reference values.

Results: The haemophilia, JIA, and SB patients respectively achieved 90-92%, 72-75% and 60-62% of predicted walking distances. There were significant associations between 6MWD and age, height and weight in the haemophilia group and 6MWD and height in the JIA group. None of the anthropometric variables was significantly related to 6MWD in the SB group. All anthropometric variables were strongly correlated with walking distance-body weight product (6Mwork) in all groups. Height explained 24% (haemophilia) and 11% (JIA) of the variance in 6MWD and 84% (haemophilia), 78% (JIA) and 73% (SB) of the variance in 6Mwork.

Conclusions: Walking distances of children with haemophilia, JIA and SB are significantly reduced compared to healthy references. Walking distance-body weight product seems to be a better outcome measure of the 6MWT compared to distance walked alone. Height is the best predictor of 6MWD and 6Mwork.