The Applicability of Existing Reference Equations for the 6-Minute Walk Test in Healthy Children and Adolescents Living in a City at a High Altitude.

Abstract

Objectives: This study aimed to evaluate the applicability of existing 6MWT reference equations to healthy children and adolescents living in a high-altitude city.

Methods: Healthy children aged 5 to 15 years attending two non-randomly selected schools in Bogotá were invited to participate in the study. All participants performed the 6MWT according to the European Respiratory Society/American Thoracic Society technical standards. To identify the model or set of 6MWT equations that best predicted individually measured 6MWT values in our population, we identified the narrowest limits of agreement (LOA) (mean difference between measured and predicted values ± 1.96 SD) after constructing Bland-Altman plots. We performed separate analyzes based on sex and onset of puberty, which was assumed to occur at 12 years of age for girls and 13 years of age for boys.

Results: 105 children and adolescents (61 girls, 58.1%) with a mean age of 10.04 years (±2.21), ranging from 6 to 15 years, were evaluated. We determined that equations derived from two different studies conducted in Brazil, de Assis, and Oliveira 6MWT equations provided the narrowest LOA in the Bland-Altman plots for the individually-measured 6MWT values for all study participants, except for the older female participants who obtained narrower LOA with the Ulrich equations.

Conclusion: For the mean walked distance of the 6MWT, we have provided information on the 6MWT predictive equations that may be most appropriate for use in healthy children living in Bogota, Colombia, a city at 2640 m altitude.