Evaluation of a Walking School Bus Program: A Cluster Randomized Controlled Trial

描述(申请人提供)：体力活动可降低患多种癌症的风险，对预防肥胖很重要，而肥胖对预防癌症也很重要。儿童积极通勤上学(ACS)以前很常见(1969-1970年为42%)，现在不常见(2009年为13%)。这一下降恰逢肥胖症流行，肥胖症对低收入和少数民族儿童的影响不成比例。增加儿童中等到剧烈的体力活动(MVPA)和降低肥胖风险的计划是必要的。步行校车(WSB)是一个创新的项目，孩子们在成人的带领下步行上下学，他们教行人安全。WSB为MVPA提供了更多的时间，该团队的WSB试验性研究报告了儿童ACS和MVPA在短期内的增加。没有随机对照试验(RCT)报道WSB计划对儿童的ACS、MVPA、行人安全和肥胖症的长期(即超过一学年)疗效。很少有研究将处于不利社会经济或种族/民族背景的儿童包括在内。主要目标是进行一项群集性随机对照试验，以评估WSB计划增加低收入、少数民族儿童的ACS和MVPA的长期效果。研究人员将采取跨学科的方法，并使用社会生态模型来考虑ACS的多个相关因素和分析水平：(1)个人层面的影响，如社会认知理论的文化适应和结构；(2)学校；(3)宏观环境影响，如邻里可步行和安全。为了在3-5年级儿童中实现项目目标，具体目标包括：SA1)在4年内从22所小学招募770名亲子双方，并进行一项整群随机对照试验，以评估WSB计划在一学年内对儿童的ACS、MVPA和BMI z分数的有效性SA2)收集和分析WSB计划对个人、学校和宏观层面对儿童ACS变化的影响的数据将被检验的主要假设包括：h1)WSB计划将在一学年增加儿童的ACS。H1a)父母的结果期望和自我效能感将在工作满意度和儿童急性冠脉综合征的变化之间起中介作用。可步行、安全和文化适应将缓和儿童急性冠脉综合征的变化。H2)WSB计划将在一个学年内增加儿童的MVPA，并降低BMI z-分数。H3)WSB计划将在一学年内提高学校层面的行人安全行为。拟议的研究将允许对儿童急性冠脉综合征、儿童急性冠脉综合征的测试主持人和调解人的变化进行最佳评估，评估MVPA和BMI z-Score的长期变化，并为未来的社区有效性试验提供关键的规划信息。 与公共健康相关：在美国，儿童肥胖症处于创纪录的高水平，低收入和少数民族儿童面临的风险最高。这个项目将测试“行走的学校” “公共汽车”项目，即儿童与成人一起步行上下学，以及它对低收入、少数民族儿童步行上学、体育活动和肥胖风险的影响。最终，这一系列研究有可能提供一个低成本、易于传播的计划，以降低高危儿童肥胖和癌症的风险。

DESCRIPTION (provided by applicant): Physical activity decreases the risk of multiple cancers and is important for obesity prevention, which in turn is important for cancer prevention. Children's active commuting to school (ACS), previously common (42 percent in 1969-1970) is now uncommon (13 percent in 2009). This decline coincided with the obesity epidemic, which disproportionately affects low-income and ethnic minority children. Programs to increase children's moderate- to-vigorous physical activity (MVPA) and lower obesity risk are necessary. The walking school bus (WSB) is an innovative program in which children walk to and from school led by adults, who teach pedestrian safety. The WSB provides additional time for MVPA, and this team's pilot WSB study reported increases to children's ACS and MVPA in the short-term. No randomized controlled trials (RCTs) have reported on long-term (i.e. over one school year) efficacy of WSB programs on children's ACS, MVPA, pedestrian safety, and adiposity. Few studies have included children from disadvantaged socioeconomic or racial/ethnic backgrounds. The Primary Goal is to conduct a cluster RCT to evaluate the long-term efficacy of a WSB program to increase low-income, ethnic minority children's ACS and MVPA. The investigators will take an interdisciplinary approach and use a social ecological model to consider multiple correlates of ACS and levels of analysis: (1) individual-level influences e.g. acculturation and constructs from social cognitive theory, (2) schools, and (3) macro-environmental influences e.g. neighborhood walkability and safety. To achieve the project goals among 3-5th grade children, the Specific Aims include: SA1) To recruit 770 child-parent dyads from 22 elementary schools over 4 years and conduct a cluster RCT to assess the efficacy of a WSB program on children's ACS, MVPA, and BMI z-score over a school-year SA2) To collect and analyze data on individual-, school-, and macro-level influences on changes to children's ACS resulting from the WSB program The Primary Hypotheses to be tested include: H1) The WSB program will increase children's ACS over a school-year. H1a) Parents' outcome expectations and self-efficacy will mediate the relationship between the WSB and changes to children's ACS. H1b) Walkability, safety, and acculturation will moderate changes to children's ACS. H2) The WSB program will increase children's MVPA and decrease BMI z-scores over a school-year. H3) The WSB program will increase school-level pedestrian safety behaviors over a school-year. The proposed research will allow for optimal assessment of changes to children's ACS, test moderators and mediators of children's ACS, evaluate long term changes to MVPA and BMI z-score, and provide crucial planning information for a future community effectiveness trial. PUBLIC HEALTH RELEVANCE: Childhood obesity is at record high levels in the US, and low-income and ethnic minority children are at highest risk. This project will test "the walking school bus" program, in which children walk to and from school with adults, and its impact on low-income, ethnic minority children's walking to school, physical activity, and risk for obesity. Ultimately, this line of research has the potential to provide a low-cost, easy to disseminate program to reduce risk of obesity and cancer for at-risk children.