The impact of natural experiments on child obesity: A systems science approach

描述（由申请人提供）：长期目标是减少儿童肥胖的流行，这已被世界卫生组织宣布为21世纪主要的公共卫生挑战之一。拟议研究的直接目的是评估肥胖相关干预措施和政策对整个洛杉矶县社区儿童早期肥胖风险的影响，洛杉矶县是一个拥有1000万人口的社会人口多样性地区。来自加州大学洛杉矶分校和加州大学伯克利分校的一个跨学科团队将与洛杉矶县公共卫生部（LACDPH）、公共卫生基金会企业WIC (PHFE WIC)[全国最大的当地机构妇女、婴儿和儿童补充营养援助计划（WIC）]和加州食品政策倡导者（CFPA）建立合作伙伴关系，为此目的使用系统科学方法开发新的评估研究方法。该研究将通过以下方式挑战和改变当前评估研究方法的范式：(1)使用来自大型行政数据库的结果数据（学龄前儿童肥胖状况）；(2)开发一种方法，用于回顾性量化解决肥胖或肥胖相关行为（饮食和体育活动）的社区努力的影响；(3)开创因果推理方法和系统科学方法的结合使用。提供结果数据的行政数据库自2003年以来一直由PHFE WIC维护；它包含每年约20万名2至5岁WIC参与者的身高和体重数据。最近对这些数据的有效性进行了评估，并显示与加州大学洛杉矶分校的一个研究小组所采取的测量结果高度相关。量化肥胖相关社区干预措施和政策对早期儿童肥胖影响的方法将使用LACDPH收集的现有数据，以及LACDPH和CFPA（两个对洛杉矶县社区解决儿童肥胖问题的努力非常了解的组织）帮助下确定的关键线人的访谈信息，以制定一个指数；该指数的编制将借鉴在烟草控制领域进行过类似工作的研究小组的经验。因果推理方法的应用，可能代表了流行病学中发展最快的方法学进展，结合系统科学方法来分析数据，将改变评估研究方法学的当前范式，允许评估可能时变干预措施的计划外混合的影响。

DESCRIPTION (provided by applicant): The long-term goal is to reduce the prevalence of child obesity, which has been declared one of the major public health challenges of the 21st century by the World Health Organization. The immediate purpose of the proposed study is to evaluate the impact of obesity-related interventions and policies on early childhood obesity risk in communities throughout Los Angeles County, a socio-demographically diverse region with a population of 10 million. An interdisciplinary team from UCLA and UC Berkeley will form partnerships with the Los Angeles County Department of Public Health (LACDPH), Public Health Foundation Enterprises WIC (PHFE WIC) [the largest local agency Supplemental Nutrition Assistance Program for Women, Infants and Children (WIC) in the country], and California Food Policy Advocates (CFPA) to develop new evaluation research methodology using systems science approaches, for this purpose. The proposed study will challenge and shift current paradigms in evaluation research methodology by (1) using outcome data (obesity status in preschool-aged children) from a large administrative database; (2) developing a methodology for retrospectively quantifying the impact of community efforts to address obesity or obesity-related behaviors (diet and physical activity), and (3) pioneering the combined use of causal inference methods and systems science approaches for the analysis. The administrative database providing the outcome data has been maintained by PHFE WIC since 2003; it contains height and weight data gathered from about ~ 200,000 two to five year old WIC participants each year. These data have recently been evaluated for validity and shown to correlate highly with measurements taken by a research team from UCLA. The methodology for quantifying the impact of obesity-related community interventions and policies on early childhood obesity will use existing data gathered by LACDPH as well as information from interviews with key informants identified with the help of LACDPH and CFPA (two organizations highly knowledgeable about community efforts to address child obesity in LA County), to develop an index; development of this index will borrow from the experiences of research groups that have conducted similar work in the field of tobacco control. The application of causal inference methods, which perhaps represent the fastest growing methodological advances in epidemiology, in combination with systems science approaches to analyze the data will shift current paradigms in evaluation research methodology, allowing for the assessment of the effects of unplanned mixtures of possibly time-varying interventions.