Evans Clare Rosenfeld, Lippert Adam M, Subramanian S V
Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
University of Colorado Denver, Denver, Colorado, USA.
J Epidemiol Community Health. 2016 Mar;70(3):260-3. doi: 10.1136/jech-2015-205833. Epub 2015 Jul 29.
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.
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.
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.
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.
众所周知，青少年体重指数（BMI）呈现出学校层面的聚集性。我们探讨了BMI的学校层面聚集性是否会持续到成年期。
将青少年时期就读学校的年轻人嵌套其中的多层次模型适用于3个结果：青少年BMI、自我报告的成人BMI和测量的成人BMI。还进行了按性别分层和按种族/族裔分层（黑人、西班牙裔、白人、其他）的分析。
学校层面的聚集性（第1波组内相关系数（ICC）=1.3%）随时间持续存在（第4波ICC=2%），并且在对性别和所有种族/族裔群体进行分层分析时结果具有可比性（使用测量的BMI时西班牙裔除外）。控制青少年时期的BMI会部分减弱这种效应。
BMI的学校层面聚集性会持续到青年期。可能的解释包括学校环境在确立行为和轨迹方面的重要性、选择类似于青少年社交网络并强化先前行为的成人社交网络，以及与BMI相关的学校招生区域特征。
