Department of Society, Human Development and Health, Harvard School of Public Health, Boston, MA 02115, USA.
Med Sci Sports Exerc. 2012 Mar;44(3):450-7. doi: 10.1249/MSS.0b013e3182300128.
Evaluate the effect of an after-school intervention on physical activity program changes and individual behaviors among children.
A quasi-experimental evaluation of a YMCA-driven environmental change intervention with 16 intervention and 16 control sites in four metropolitan areas in the United States. Intervention sites participated in learning collaboratives designed to promote physical activity and nutrition through environmental change, educational activities, and parent engagement. Behavioral foci included increasing overall physical activity levels as well as combined moderate and vigorous physical activity and vigorous physical activity. Outcomes were assessed longitudinally using preintervention and follow-up surveys of program implementation and accelerometer measures of physical activity. ActiGraph accelerometer data were collected from a sample of 212 children, ages 5-11 yr, attending the programs. On average, 3 d of data were gathered per child. Reliability of the accelerometer counts averaged 0.78. Multivariate regression models were used to control for potential confounding variables and to account for clustering of observations.
Data indicate greater physical activity increases in children in intervention versus control sites after modest intervention implementation. Controlling for baseline covariates, children in intervention sites showed greater increases in average physical activity level than in control sites (76 counts per minute, P = 0.037, 95% confidence interval (CI) = 8.1-144) and more minutes of moderate and vigorous physical activity (10.5 min·d(-1), P = 0.017, 95% CI = 1.5-18.6), minutes of moderate physical activity (5.6 min·d(-1), P = 0.020, 95% CI = 0.99-10.2), and minutes of vigorous physical activity (5.1 min·d(-1), P = 0.051, 95% CI = 0.21-9.93).
Results indicate significant increases in daily physical activity among children in intervention versus control sites. This study documents the effectiveness of an environmental change approach in an applied setting.
评估课后干预对儿童身体活动项目变化和个体行为的影响。
在美国四个大都市区的 16 个干预和 16 个对照点进行了一项基于基督教青年会驱动的环境变化干预的准实验评估。干预点参与了学习合作，旨在通过环境变化、教育活动和家长参与来促进身体活动和营养。行为重点包括提高整体身体活动水平以及结合中等强度和剧烈身体活动和剧烈身体活动。使用方案实施的预干预和随访调查以及身体活动的加速度计测量结果，对结果进行了纵向评估。从参加该项目的 212 名 5-11 岁儿童中收集了 ActiGraph 加速度计数据。每个孩子平均收集了 3 天的数据。加速度计计数的可靠性平均为 0.78。使用多变量回归模型控制潜在的混杂变量，并考虑到观察结果的聚类。
数据表明，在适度实施干预后，干预点的儿童身体活动增加幅度大于对照组。控制基线协变量后，干预点的儿童比对照组的平均身体活动水平增加更多（76 次/min，P=0.037，95%置信区间（CI）=8.1-144），并且更多的分钟中高强度身体活动（10.5 min·d（-1），P=0.017，95%CI=1.5-18.6），中等强度身体活动分钟（5.6 min·d（-1），P=0.020，95%CI=0.99-10.2），以及剧烈身体活动分钟（5.1 min·d（-1），P=0.051，95%CI=0.21-9.93）。
结果表明，干预组儿童的日常身体活动显著增加。这项研究记录了在应用环境中环境变化方法的有效性。
