A Longitudinal Study of Changes Observed in the 6-Min Walk Test Over a 4-Month Period in Healthy 6 to 12-Year-Old Children

Abstract Simpler and less expensive field tests, such as the 6-min walk test, have been employed to evaluate exercise tolerance in chronic paediatric conditions. However, patterns of longitudinal change for outcome measures could show initial gains attributable to normal growth and development in children. We aimed to verify the effect of growth on the distance achieved in 6-min walk test in children 6 to 12 years of age over a 4-month period. Healthy children from 6–12 years of age were recruited. Two trials of the 6-min walk test were performed on the same day and after a 4-month period. We employed the intraclass correlation coefficient to assess test-retest reliability when the 6-min walk test was applied with a 4-month time interval. 59 children (28 boys and 31 girls) were assessed. The distance covered in the 6-min walk test and anthropometric variables showed a statistically significant increase after 4 months. After 4 months, we established a 12% change from the initial measurement (79.69 m) as the minimal detectable change for a 90% confidence level, while a 15% change (94.66 m) was determined as the minimal detectable change for a 95% confidence level. Conclusions: The distance covered in the 6-min walk test improved as the children’s height increased, establishing a 12% change in the score of at least 79.69 m as the most appropriate value in interpreting longitudinal functional performance data when assessing exercise tolerance in healthy children aged 6 to 12 years.