Using Data-Driven Insights to Explore the Variability in Pupils' Physical Activity Between English Primary Schools.

Background: Characterizing interindividual differences in physical activity within schools and understanding potential drivers of these differences may support the development of improved strategies to increase in-school physical activity.

Methods: Anonymized physical activity data from a school-specific wrist-worn device were obtained from 17,043 pupils and 2555 staff from 165 primary schools in England. Additional school information included UK government school data, area-level deprivation, and estimated playground area. Descriptive statistics were calculated, and data visualizations were used to explore within- and between-school differences. Multilevel models were used to explore the associations between children's in-school physical activity and school variables, with pupils nested within schools, adjusted for individual characteristics.

Results: There was large variation in physical activity between schools. Some schools accumulated twice the amount of physical activity within the school day compared with other schools, with physical activity ranging from 4253 to 8356 steps per school day or 16 to 39 minutes of moderate to vigorous physical activity per school day. School-level data, such as playground space and government school ratings, did not explain between-school variance. Although boys were generally more active than girls in most schools, some schools had more equitable physical activity, and in a small number of schools (∼5%), girls were more active than boys.

Conclusions: There is considerable heterogeneity in physical activity levels between English primary schools. Technology-enabled surveillance from wearable devices can be used to identify schools needing greater support and facilitate learning from those with higher and more equitable physical activity among pupils.