Evaluation of a walking school bus for promoting physical activity in youth

Using objective PA assessment only in a subpopulation may have introduced selection bias.

“which may have introduced selection bias”

A number of included studies used objective PA assessment only in a subpopulation.

“A number of studies used objective PA assessment only in a subpopulation”

In a subset of children with objective physical activity measurements in that trial, proportions reporting active commuting were 71% in intervention and 25% in controls.

“In a subset of children who received objective physical activity measurements, these proportions were 71% and 25%, respectively.”

In both walking school bus studies, compared with control schools, the program increased the proportion of children who reported walking to school.

“In both studies, compared with control schools, the program increased the proportion of children who reported that they were walking to school.”

Although active commuting was increased in walking school bus trials, there were no significant differences in BMI or percentage body fat between groups, even after 2 years.

“However, although active commuting was increased, there were no significant differences in BMI or percentage of body fat between groups, even after 2 years.”

After 2 years in one walking school bus trial, 36% of children in the intervention reported active commuting on at least 50% of school days versus 26% of controls.

“For instance, after 2 years in 1 trial, 36% of children in the intervention reported active (walking or bicycling) commuting on at least 50% of school days versus 26% of controls.265”

Children who were frequent walkers had significantly lower BMI (−0.77 kg/m2) and percentage body fat (−4.0%).

“Children who were frequent walkers had a significantly lower BMI (−0.77 kg/m2) and percentage of body fat (−4.0%)265; such observational, non–intention-to-treat analyses should be interpreted cautiously.”