The school policy, social, and physical environment and change in adolescent physical activity: An exploratory analysis using the LASSO.

Paul Wilkinson,Kathryn L Weston,Helen Elizabeth Brown,Campbell Foubister,Kirsten Corder,Caroline H D Croxson,Esther M F Van Sluijs,Anna Vignoles,Edward C F Wilson

doi:10.1371/journal.pone.0249328

Abstract

PurposeWe examined the association between the school policy, social and physical environment and change in adolescent physical activity (PA) and explored how sex and socioeconomic status modified potential associations.MethodsData from the GoActive study were used for these analyses. Participants were adolescents (n = 1765, mean age±SD 13.2±0.4y) from the East of England, UK. Change in longitudinal accelerometer assessed moderate-to-vigorous physical activity (MVPA) was the outcome. School policy, social and physical environment features (n = 267) were exposures. The least absolute shrinkage and selection operator variable selection method (LASSO) was used to determine exposures most relevant to the outcome. Exposures selected by the LASSO were added to a multiple linear regression model with estimates of change in min/day of MVPA per 1-unit change in each exposure reported. Post-hoc analyses, exploring associations between change in variables selected by the LASSO and change in MVPA, were undertaken to further explain findings.FindingsNo school policy or physical environment features were selected by the LASSO as predictors of change in MVPA. The LASSO selected two school social environment variables (participants asking a friend to do physical activity; friend asking a participant to do physical activity) as potential predictors of change in MVPA but no significant associations were found in subsequent linear regression models for all participants (β [95%CI] -1.01 [-2.73;0.71] and 0.65 [-2.17;0.87] min/day respectively). In the post-hoc analyses, for every unit increase in change in participants asking a friend to do PA and change in a friend asking participants to do PA, an increase in MVPA of 2.78 (1.55;4.02) and 1.80 (0.48;3.11) min/day was predicted respectively.ConclusionsThe school social environment is associated with PA during adolescence. Further exploration of how friendships during adolescence may be leveraged to support effective PA promotion in schools is warranted.

Highlights

Physical activity in adolescence is positively associated with improvements to metabolic health [1], mental health [2] and maths performance [3]
The results of the GoActive trial showed that adolescents become more physically inactive over time with no difference found between control and intervention participants’ physical activity [13], the cohort for this study included all participants from control and intervention schools
A total of 267 school environment features were included in the LASSO variable selection technique, a full list of variables included in the LASSO is shown in S1 Table

Summary

Introduction

Physical activity in adolescence is positively associated with improvements to metabolic health [1], mental health [2] and maths performance [3]. Adolescents’ physical activity levels are much lower than recommended [4] and there is a need to find ways to increase adolescent physical activity. A common critique of school-based physical activity strategies is the focus on behaviour change at the individual level and lack of acknowledgement of the multidimensional influences on adolescent physical activity within schools [6]. Adopting a socioecological approach and intervening at multiple levels to address the wider school environment may bring rise to sustained increases in adolescent physical activity [7]. This may support effective intervention implementation, which is a major challenge faced by schools, when translating evidence-based interventions into routine practice [8]

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