Neighborhood Safety and Children's Physical Activity, Inactivity and BMI

描述（由申请人提供）：本研究将使用纵向模型对全国具有代表性的幼儿园儿童样本进行估计，研究社区安全的客观和感知措施如何影响幼儿的身体活动，久坐行为和体重指数（BMI）。我们的研究有三个具体目的：1。检查邻里安全的感知和客观措施之间的相关性。2. 估计面板数据模型，以检查感知和客观社区安全措施的变化是否影响儿童的身体活动、久坐行为和BMI。3. 检查邻里安全、体力活动、久坐行为和BMI的感知和客观测量的影响是否因儿童的社会经济特征而异。我们将使用幼儿纵向研究-幼儿园班（ECLS-K）的数据，这是一个具有全国代表性的幼儿园样本，具有一年级，三年级，五年级和八年级的随访数据。身体活动、不活动、身体质量指数和社区安全感知措施（家长、学校管理人员和采访者报告）在ECLS-K中有多个波。通过将ECLS-K每年与统一犯罪报告中的县级犯罪数据和来自个别警察部门的方便样本的人口普查区级犯罪数据联系起来，将构建社区安全的客观措施。我们的分析方法依赖于儿童固定效应模型，该模型通过利用因变量和同一儿童的社区安全随时间的变化来确定社区安全的影响。结果将按关键的社会经济特征进行分类，以便了解它们与社区安全的相互作用。此外，从多个角度和不同水平的地理精度对社区安全的感知和客观测量结果进行比较，将有助于理清社会环境中这一整体方面的重要性。

DESCRIPTION (provided by applicant): This study will examine how objective and perceived measures of neighborhood safety influence young children's physical activity, sedentary behavior, and body mass index (BMI) using longitudinal models estimated on a nationally representative sample of kindergartners. Our study has three specific aims: 1. Examine the correlation between perceived and objective measures of neighborhood safety. 2. Estimate panel data models to examine whether changes in perceived and objective measures of neighborhood safety influence children's physical activity, sedentary behavior, and BMI. 3. Examine whether the influence of perceived and objective measures of neighborhood safety physical activity, sedentary behavior, and BMI vary by children's socio-economic characteristics. We will use data from the Early Childhood Longitudinal Study - Kindergarten Class (ECLS-K), a nationally representative sample of kindergartners with follow-up data in the first, third, fifth and eighth grades. Physical activity, inactivity, BMI and perceived measures of neighborhood safety (parent, school administrator, and interviewer reports) are available in multiple waves in the ECLS-K. Objective measures of neighborhood safety will be constructed by linking each year of the ECLS-K to county level crime data from the Uniform Crime Reports and census tract level crime data from a convenience sample of individual police departments. Our analytical approach relies on child fixed effects models that indentify the effects of neighborhood safety by leveraging changes in the dependent variables and neighborhood safety over time for the same child. Results will be disaggregated by key socioeconomic characteristics in order to understand their interaction with neighborhood safety. In addition, comparison of results using perceived and objective measures of neighborhood safety from multiple perspectives and various levels of geographic precision will be useful in disentangling the importance of this integral aspect of the social environment. Public Health Relevance: This study can inform policy interventions that address neighborhood safety and the physical activity behaviors of young children and how such interventions may be influenced by socio-economic characteristics. The study also provides greater insight on parental decision-making by exploiting a rich dataset of perceived and objective safety measures. Similar to school-based physical activity interventions, neighborhood safety programs have the ability to affect large numbers of children making them a potentially important part of a broader public health strategy.