title: A repeated cross-sectional study examining the school impact on child weight status.
abstract: OBJECTIVE
  The aim of this study is to examine whether there is a differential impact of primary schools upon children's weight status.
  
  
  METHODS
  A 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.
  
  
  RESULTS
  Although 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.
  
  
  CONCLUSIONS
  The 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.
authors.affiliation: Institute of Health Research, University of Exeter Medical School (formerly Peninsula College of Medicine and Dentistry), Veysey Building, Salmon Pool Lane, Exeter, Devon EX2 4SG, United Kingdom; Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, St. Luke's Campus, Heavitree Road, Exeter, Devon EX1 2LU, United Kingdom. Electronic address: a.j.williams@exeter.ac.uk.
authors.forename: Andrew James
authors.initials: AJ
authors.lastname: Williams
authors.affiliation: Institute of Health Research, University of Exeter Medical School (formerly Peninsula College of Medicine and Dentistry), Veysey Building, Salmon Pool Lane, Exeter, Devon EX2 4SG, United Kingdom. Electronic address: k.m.wyatt@exeter.ac.uk.
authors.forename: Katrina Mary
authors.initials: KM
authors.lastname: Wyatt
authors.affiliation: Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, St. Luke's Campus, Heavitree Road, Exeter, Devon EX1 2LU, United Kingdom. Electronic address: c.a.williams@exeter.ac.uk.
authors.forename: Craig Anthony
authors.initials: CA
authors.lastname: Williams
authors.affiliation: Institute of Health Research, University of Exeter Medical School (formerly Peninsula College of Medicine and Dentistry), Veysey Building, Salmon Pool Lane, Exeter, Devon EX2 4SG, United Kingdom. Electronic address: stuart.logan@exeter.ac.uk.
authors.forename: Stuart
authors.initials: S
authors.lastname: Logan
authors.affiliation: Institute of Health Research, University of Exeter Medical School (formerly Peninsula College of Medicine and Dentistry), Veysey Building, Salmon Pool Lane, Exeter, Devon EX2 4SG, United Kingdom. Electronic address: w.e.henley@exeter.ac.uk.
authors.forename: William E
authors.initials: WE
authors.lastname: Henley
mesh_terms: D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004739:England / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D015233:Models, Statistical; D009765:Obesity / Q000453:epidemiology* / Q000517:prevention & control; D015995:Prevalence; D012574:Schools / Q000706:statistics & numerical data*; D012923:Social Class
keywords: Education; League tables; Obesity; Value-added
references.citation: Health Place. 2012 May;18(3):504-14
references.pmid: 22381422
references.citation: Prev Med. 2014 May;62:193-200
references.pmid: 24518005
references.citation: Int J Behav Nutr Phys Act. 2013 Aug 22;10:101
references.pmid: 23965018
references.citation: Arch Dis Child. 1995 Jul;73(1):25-9
references.pmid: 7639544
references.citation: Health Place. 2011 May;17(3):710-6
references.pmid: 21474361
references.citation: Obes Rev. 2012 Mar;13(3):214-33
references.pmid: 22070186
references.citation: Soc Sci Med. 2008 Jul;67(2):341-9
references.pmid: 18439737
references.citation: Obes Rev. 2009 Jan;10(1):110-41
references.pmid: 18673306
references.citation: Int J Obes (Lond). 2012 Jan;36(1):45-52
references.pmid: 22005718
references.citation: Nutr Res Rev. 2007 Jun;20(1):29-45
references.pmid: 19079859
references.citation: BMJ. 1990 Nov 3;301(6759):1031-4
references.pmid: 2249053
references.citation: Lancet. 2011 Apr 23;377(9775):1438-47
references.pmid: 21474174
references.citation: Biometrics. 1989 Mar;45(1):255-68
references.pmid: 2720055
references.citation: BMJ. 1998 Jun 6;316(7146):1701-4; discussion 1705
references.pmid: 9614016
references.citation: Int J Qual Health Care. 2004 Aug;16(4):309-15
references.pmid: 15252005