Physical activity levels of children and adolescents with moderate-to-severe intellectual disability.

The analysis included 68 of 130 children, and 11 participants did not wear the accelerometer at all. Only children who could walk independently and attended specialized day program centres were studied, so the results do not apply to children who cannot walk independently or attend other settings. Swimming and other water-based activities were not captured by the accelerometer, and parent event sheets were rarely completed, so activity volume may be underestimated. The intellectual disability-specific cut-points were developed for children aged 8 to 11 years, but participants were aged 2 to 18 years, so classification accuracy outside that age range is uncertain. The study was cross-sectional, so it cannot show that poor motor development causes low physical activity. The regression models explained only a small part of the variation, and the authors used many predictors, so other factors likely influenced activity levels. The 47% meeting recommendation depends on the cut-points used; the authors reported that using typical child cut-points gave 4%.

Do not read the 47% meeting the recommendation as reassurance. More than half did not meet it, and the result depends on the intellectual disability-specific cut-points used.