Reference Values and Prediction Equation for Six-Minute Walk Distance in Children Aged 6-12 Years

Abstract

The Six-Minute Walk Test (6MWT) is a self-paced, inexpensive sub-maximal exercise test used as a reliable and valid measure
of exercise capacity in children and adolescents. The American Thoracic Society has recommended establishment of specific
reference values for Six-Minute Walk Distance (6MWD) for each population in various age groupings and ethnicities. However,
limited information exists on reference values for different age groups in Nigeria. This study was designed to generate reference
values for apparently healthy Nigerian children, aged 6-12 years. . This cross-sectional study involving 334 apparently healthy
Nigerian children was approved by the appropriate Health Research Ethics Committee. Their physical and selected physiological
characteristics were measured and determined, as appropriate. Each participant had a single trial of the 6MWT and distance
covered was recorded. Data were analysed using both descriptive and inferential statistics at p<0.05. Results showed the mean
6MWD of all participants was 504.38± 66.16m. The males had a significantly higher 6MWD. Age, weight and height, correlated
significantly with the 6MWD. Prediction equations were derived from the physical characteristics of the children for 6MWD.
Height and BMI were found to be significant predictors of 6MWD in all the participants. Percentiles and quartile deviations were
also reported. The outcome of this study provided the reference value of 456m-506m for the Six-Minute Walk Distance among
the apparently healthy Nigerian children aged 6 to 12 years. The prediction equation derived in this study has both clinical and
field usefulness with regards physical performance by children of this age-range.