Linking dynamic environments with childhood obesity

描述(由申请人提供)：建议的是一项培训和研究计划，使用正在进行的纵向研究来调查动态环境对儿童肥胖的影响。肥胖和久坐行为对儿童健康的威胁越来越普遍，这可能反映了儿童及其家庭经历的身体活动机会、食物环境和社会背景的变化。建筑环境的特征已经与儿童和成年人的健康行为和体重联系在一起，但这种联系的因果性质尚不清楚。一个关键的挑战是区分对观察到的关联的相互矛盾的解释：社区对个人体育活动和健康的影响，以及活跃和健康的个人选择支持自己生活方式的社区的倾向。拟议的研究有可能证实或缓和先前关于这一主题的研究结论。以前的横断面研究大多假设居住环境是静态的，而拟议的项目将使用关于居住流动性和动态环境的数据，以更好地建立所谓的环境原因和健康影响的时间序列。将利用现有的社会背景衡量标准来显示建筑环境关联如何与社会背景关联进行比较或相互作用。我将选择分析方法来充分利用这些数据，并评估相互竞争的因果假设。我将分析两项纵向研究中关于建筑环境、社会环境、体力活动和体重的数据。第一项是《脆弱家庭儿童福祉研究》，该研究对美国大城市的4898名儿童进行了出生队列研究，对单亲家庭进行了过度抽样，目前正在收集9岁儿童的数据。第二项是Healthy Places试验，这是对新建的Smart Growth开发项目进行的自然实验评估，其建成的环境特征预计将对当地的社交网络和亲子对的身体活动产生有益影响。这些队列中的分析将解决特定的假设，重点是建筑环境、社会背景及其相互作用的肥胖效应。除了使用纵向和自然的实验设计外，我还将探索一系列分析策略，以测试观察到的关联的因果性质。特别是，我将通过分层分析、结构方程建模、潜在轨迹分析、有向无环图、倾向得分匹配和工具变量分析来检查排序、特异性和选择。拟议的研究将得到以下方面的经验和教学培训的补充：(1)减少健康差距的环境方法，(2)社会背景和健康的理论和衡量，(3)轨迹分析和生命周期流行病学，以及(4)提供因果推断的研究设计和分析方法。这项研究和培训将使我能够启动一项关于城市建成和社会环境塑造儿童身体活动和健康的独立研究计划。

DESCRIPTION (provided by applicant): Proposed is a program of training and research using ongoing longitudinal studies to investigate the effects of dynamic environments on childhood obesity. Obesity and sedentary behavior are increasingly common threats to childhood health, likely reflecting changes to the physical activity opportunities, food environment, and social contexts experienced by children and their families. Characteristics of the built environment have been linked to health behaviors and weight of both children and adults, but the causal nature of the link is not clear. A key challenge is to distinguish between competing explanations for the observed associations: the effect of neighborhoods on individual physical activity and health versus the tendency for active and healthy individuals to select neighborhoods that support their lifestyle. The proposed research has the potential to corroborate or temper the conclusions of previous research on this topic. Whereas previous cross-sectional studies have largely assumed that residential environments are static, the proposed project will use data on residential mobility and dynamic environments to better establish the temporal sequence of purported environmental causes and health effects. Available social context measures will be leveraged to show how built environment associations compare to or interact with those of social context. I will select analytical approaches to take full advantage of these data and to assess competing causal hypotheses. I will analyze data on built environments, social context, physical activity, and weight from two longitudinal studies. The first is the Fragile Families Study of Childhood Wellbeing, a birth cohort study of 4,898 children in large US cities that oversampled single parent families and is currently collecting data at age 9. The second is the Healthy PLACES trial a natural experimental evaluation of a newly built Smart Growth development, with built environment characteristics expected to have beneficial effects on local social networks and physical activity from parent-child pairs. Analyses in these cohorts will address specific hypotheses focusing on the obesogenic effects of the built environment, social context, and their interaction. In addition to the use of longitudinal and natural experimental designs, I will explore a range of analytical strategies selected to test the causal nature of observed associations. In particular, I will examine sequencing, specificity, and selection through stratified analyses, structural equation modeling, latent trajectory analysis, directed acyclic graphs, propensity score matching, and instrumental variable analysis. The proposed research will be complemented by experiential and didactic training in (1) environmental approaches to decrease health disparities, (2) theory and measurement of social context and health, (3) trajectory analysis and lifecourse epidemiology, and (4) study designs and analytical approaches to inform causal inference. This research and training will enable me to launch a program of independent research on the urban built and social environments shaping childhood physical activity and health.