Pulakka A, Cheung Y B, Ashorn U, Penpraze V, Maleta K, Phuka J C, Ashorn P
Department of International Health, University of Tampere School of Medicine, Tampere, Finland.
Acta Paediatr. 2013 Dec;102(12):1192-8. doi: 10.1111/apa.12412.
To test the feasibility and validity of the ActiGraph GT3X accelerometer in measuring physical activity of rural Malawian toddlers.
Fifty-six children aged 16.0-18.5 months wore the accelerometer on their right hip for 7 days. We analysed days with a minimum of 600 min of wear time, excluding night time and periods when the unit registered zero for 20 consecutive minutes. The first and last days were excluded as they were incomplete. Accelerometer counts were compared with coded free play video recordings to define median accelerometer counts for sedentary, light, moderate and vigorous activity. Count cut points were defined for moderate to vigorous physical activity, with predictive validity assessed using a second set of video recordings.
Median wear time was 797 min/day, with 79% of participants completing at least four eligible days. Accelerometer counts were significantly higher for observed moderate to vigorous physical activity, than lighter activity, with cut points of 208 counts/15 sec for vector magnitude and 35 counts/15 sec for vertical axis, showing sensitivity of 94.2% and 84.1% and specificity of 90.9% and 84.6%, respectively.
The accelerometer proved a feasible and valid method of assessing physical activity among Malawian toddlers.
测试ActiGraph GT3X加速度计在测量马拉维农村幼儿身体活动方面的可行性和有效性。
56名年龄在16.0 - 18.5个月的儿童将加速度计佩戴在右髋部，持续7天。我们分析了佩戴时间至少为600分钟的天数，不包括夜间以及设备连续20分钟记录为零的时间段。第一天和最后一天被排除，因为它们不完整。将加速度计计数与编码的自由玩耍视频记录进行比较，以确定久坐、轻度、中度和剧烈活动的加速度计计数中位数。为中度至剧烈身体活动定义计数切点，并使用第二组视频记录评估预测效度。
平均佩戴时间为每天797分钟，79%的参与者至少完成了四个合格天数。观察到的中度至剧烈身体活动的加速度计计数显著高于轻度活动，向量大小的切点为208次计数/15秒，垂直轴的切点为35次计数/15秒，灵敏度分别为94.2%和84.1%，特异性分别为90.9%和84.6%。
加速度计被证明是评估马拉维幼儿身体活动的一种可行且有效的方法。
