title: The persistent clustering of adult body mass index by school attended in adolescence.
abstract: BACKGROUND
  It is well known that adolescent body mass index (BMI) shows school-level clustering. We explore whether school-level clustering of BMI persists into adulthood.
  
  
  METHODS
  Multilevel models nesting young adults in schools they attended as adolescents are fit for 3 outcomes: adolescent BMI, self-report adult BMI and measured adult BMI. Sex-stratified and race/ethnicity-stratified (black, Hispanic, white, other) analyses were also conducted.
  
  
  RESULTS
  School-level clustering (wave 1 intraclass correlation coefficient (ICC)=1.3%) persists over time (wave 4 ICC=2%), and results are comparable across stratified analyses of both sexes and all racial/ethnic groups (except for Hispanics when measured BMIs are used). Controlling for BMI in adolescence partially attenuates this effect.
  
  
  CONCLUSIONS
  School-level clustering of BMI persists into young adulthood. Possible explanations include the salience of school environments in establishing behaviours and trajectories, the selection of adult social networks that resemble adolescent networks and reinforce previous behaviours, and characteristics of school catchment areas associated with BMI.
authors.affiliation: Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
authors.forename: Clare Rosenfeld
authors.identifier: http://orcid.org/0000-0002-9862-9506
authors.initials: CR
authors.lastname: Evans
authors.affiliation: University of Colorado Denver, Denver, Colorado, USA.
authors.forename: Adam M
authors.initials: AM
authors.lastname: Lippert
authors.affiliation: Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
authors.forename: S V
authors.initials: SV
authors.lastname: Subramanian
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D055361:Multilevel Analysis; D009765:Obesity / Q000208:ethnology*; D015995:Prevalence; D044469:Racial Groups / Q000706:statistics & numerical data; D012574:Schools; D014481:United States / Q000453:epidemiology
keywords: Life course epidemiology; MEDICAL SOCIOLOGY FQ; MULTILEVEL MODELLING; OBESITY; SOCIAL EPIDEMIOLOGY