A repeated cross-sectional study examining the school impact on child weight status

Abstract

ObjectiveThe aim of this study is to examine whether there is a differential impact of primary schools upon children's weight status.MethodsA repeated cross-sectional study was undertaken using five years (2006/07–2010/11) of National Child Measurement Programme data, comprising 57,976 children (aged 4–5 (Reception) and 10–11 (Year 6) years) from 300 primary schools across Devon, England. Examining each year separately, the schools were ranked according to their observed and residual (having accounted for school and neighbourhood clustering and pupil ethnicity and socioeconomic status) school mean body mass index standard deviation score (BMI-SDS). Subtracting the Reception from the Year 6 mean residuals gave ‘value-added’ scores for each school which were also ranked. The rankings were compared within and across the years to assess consistency.ResultsAlthough pupil BMI-SDS was high, > 97% of the variation in BMI-SDS was attributable to environments other than the school. The ‘value-added’ by each school was only poorly correlated with the observed and residual pupil BMI-SDS; but none of the rankings were consistent across the five years.ConclusionThe inconsistency of the rankings and the small variation in BMI-SDS at the level of the school suggests that there is no systematic differential impact of primary schools upon pupil weight status.

Exploring the Potential of a School Impact on Pupil Weight Status: Exploratory Factor Analysis and Repeat Cross-Sectional Study of the National Child Measurement Programme

“…Neighbourhood has been considered an important context in the child’s life. However, our previous research, and that of Procter et al [ 19 ], found cross-classification by neighbourhood to have little impact upon the results, and hence cross-classification was not undertaken in the present study [ 20 ].…”

“…We previously undertook an analysis replicating the methods proposed by Procter et al [ 19 ] across five years [ 20 ]. Although we were able to replicate their findings within any single year, each schools impact (value-added ranking) varied considerably across the five years [ 20 ].…”

“…We previously undertook an analysis replicating the methods proposed by Procter et al [ 19 ] across five years [ 20 ]. Although we were able to replicate their findings within any single year, each schools impact (value-added ranking) varied considerably across the five years [ 20 ]. We therefore concluded that the effect observed by Procter et al [ 19 ] did not reflect a systematic differential school impact on pupil weight status [ 20 ].…”

“…Although we were able to replicate their findings within any single year, each schools impact (value-added ranking) varied considerably across the five years [ 20 ]. We therefore concluded that the effect observed by Procter et al [ 19 ] did not reflect a systematic differential school impact on pupil weight status [ 20 ]. However, the possibility remains that there are features of the school context that influence weight status but that these are not evident when studying consistency of school rankings over time because the rankings are sensitive to other factors including the characteristics of the pupils in each yearly cohort [ 21 ].…”

Cluster randomised controlled trial and economic and process evaluation to determine the effectiveness and cost-effectiveness of a novel intervention [Healthy Lifestyles Programme (HeLP)] to prevent obesity in school children

“…36 For our primary outcome measure of BMI SDS, we determined the number of schools required (assuming an average of 35 Year 5 children per school, with coefficient of variation of 0.5, and an ICC of 0.02) to detect a between-group difference in BMI SDS of 0.25 units at 24 months with 90% power, a two-sided 5% significance level, a standard deviation (SD) of 1.3 and adjusting for baseline BMI SDS (assuming within-child correlation of 0.8). We allowed for a conservative 20% loss to follow-up or missing data at 24 months.…”