Department of Psychology, University of Texas, El Paso, USA.
Am J Public Health. 2011 Oct;101(10):1907-13. doi: 10.2105/AJPH.2011.300177. Epub 2011 Aug 18.
We evaluated the effectiveness and spillover of an after-school health education and physical activity program among Hispanic elementary school children.
In fall 2008, students in third through fifth grades in 6 schools in El Paso, Texas (n = 901), were randomized to intervention (n = 292 participants) or control (n = 354) classrooms (4 unknown). Intervention classrooms also contained a spillover group (n = 251) that did not join the after-school program but that completed measurements and surveys. The intervention was a 12-week culturally tailored after-school program meeting twice a week. Four-month outcomes were body mass index, aerobic capacity, and dietary intentions and knowledge. We calculated intervention exposure as the proportion of after-school participants per classroom.
Intervention exposure predicted lower body mass index (P = .045), higher aerobic capacity (P = .012), and greater intentions to eat healthy (P = .046) for the classroom at follow-up. Intervention effectiveness increased with increasing proportions of intervention participants in a classroom. Nonparticipants who had classroom contact with program participants experienced health improvements that could reduce their risk of obesity.
Spillover of beneficial intervention effects to nonparticipants is a valuable public health benefit and should be part of program impact assessments.
我们评估了一项针对西班牙裔小学生的课外健康教育和体育活动项目的效果及其外溢效应。
2008 年秋季，德克萨斯州埃尔帕索 6 所学校三至五年级的学生（n=901）被随机分配到干预（n=292 名参与者）或对照组（n=354）班级（4 个未知）。干预班级还包含一个溢出组（n=251），他们没有参加课外项目，但完成了测量和调查。干预是一个为期 12 周的文化适应的课外项目，每周两次。四个月的结果是体重指数、有氧能力以及饮食意图和知识。我们将干预暴露定义为每个班级参加课外项目的学生比例。
干预暴露预测班级在随访时的体重指数较低（P=0.045）、有氧能力较高（P=0.012）和更健康饮食的意图较大（P=0.046）。随着班级中干预参与者比例的增加，干预的效果也随之增加。与项目参与者有课堂接触的非参与者经历了健康改善，这可以降低他们肥胖的风险。
将有益的干预效果外溢到非参与者是一项有价值的公共卫生效益，应成为项目影响评估的一部分。
