Background: The 6-min walk test (6MWT) is a simple, accurate and safe method to measure functional exercise capacity. The 6MWT is increasingly used in children to predict morbidity and mortality from cardiopulmonary disease, to assess functional capacity and measure disease progression in chronic childhood conditions such as muscular dystrophy.
Objective and hypotheses: To provide smooth reference curves for the 6-min walk distance (6MWD) in healthy children aged 419 years and to enable calculation of sex-, age- and height-specific Z-scores for use in clinical practice.
Method: 696 healthy Caucasian children and adolescents (328 girls) aged 419 years were included in the study. The modified 6MWT measures the distance walked by the participant in 6-min using a measuring wheel with interchangeable handlebars. Smooth sex-specific 6MWD centile charts for age and height were created using the Altman model.
Results: Sex-specific centile curves were created from the best fitting equations, showing the 2nd, 50th and 98th centiles for age and height. In age specific centile curves for girls, the 6MWD increased between 4 and 11 years of age, plateaued thereafter and dipped slightly in those aged 15 years and above. In boys, the 6MWD increased from 4 to 19 years of age with the maximum rise between 6 and 14 years of age. Overall boys covered greater 6MWD in comparison to girls.
Conclusion: Our study provides smooth reference curves for the 6MWT in a large cohort of healthy Caucasian children aged 419 years for easy use in clinical practice, and enables the calculation of sex-, age- and height- specific Z-scores. These centile charts help in assessing exercise capacity, measure disease severity and response to intervention.
18 Sep 2014 - 20 Sep 2014