Department of Movement and Sport Sciences, University of Ghent, Watersportlaan 2, 9000 Ghent, Belgium.
Int J Behav Nutr Phys Act. 2011 Jun 26;8:67. doi: 10.1186/1479-5868-8-67.
Accelerometers are considered to be the most promising tool for measuring physical activity (PA) in free-living young children. So far, no studies have examined the feasibility and validity of accelerometer measurements in children under 3 years of age. Therefore, the purpose of the present study was to examine the feasibility and validity of accelerometer measurements in toddlers (1- to 3-year olds).
Forty-seven toddlers (25 boys; 20 ± 4 months) wore a GT1M ActiGraph accelerometer for 6 consecutive days and parental perceptions of the acceptability of wearing the monitor were assessed to examine feasibility. To investigate the validity of the ActiGraph and the predictive validity of three ActiGraph cut points, accelerometer measurements of 31 toddlers (17 boys; 20 ± 4 months) during free play at child care were compared to directly observed PA, using the Observational System for Recording Physical Activity in Children-Preschool (OSRAC-P). Validity was assessed using Pearson and Spearman correlations and predictive validity using area under the Receiver Operating Characteristic curve (ROC-AUC).
The feasibility examination indicated that accelerometer measurements of 30 toddlers (63.8%) could be included with a mean registration time of 564 ± 62 min during weekdays and 595 ± 83 min during weekend days. According to the parental reports, 83% perceived wearing the accelerometer as 'not unpleasant and not pleasant' and none as 'unpleasant'. The validity evaluation showed that mean ActiGraph activity counts were significantly and positively associated with mean OSRAC-P activity intensity (r = 0.66; p < 0.001; n = 31). Further, the correlation among the ActiGraph activity counts and the OSRAC-P activity intensity level during each observation interval was significantly positive (ρ = 0.52; p < 0.001; n = 4218). Finally, the three sedentary cut points exhibited poor to fair classification accuracy (ROC-AUC: 0.56 to 0.71) while the three light PA (ROC-AUC: 0.51 to 0.62) and the three moderate-to-vigorous PA cut points (ROC-AUC: 0.53 to 0.57) demonstrated poor classification accuracy with respect to detecting sedentary behavior, light PA and moderate-to-vigorous PA, respectively.
The present findings suggest that ActiGraph accelerometer measurements are feasible and valid for quantifying PA in toddlers. However, further research is needed to accurately identify PA intensities in toddlers using accelerometry.
加速度计被认为是测量自由活动的幼儿身体活动（PA）的最有前途的工具。迄今为止，尚无研究检查在 3 岁以下儿童中使用加速度计测量的可行性和有效性。因此，本研究的目的是检查加速度计在幼儿（1-3 岁）中的测量的可行性和有效性。
47 名幼儿（25 名男孩；20±4 个月）连续佩戴 GT1M ActiGraph 加速度计 6 天，并评估父母对佩戴监测器的可接受性的看法，以检查可行性。为了研究 ActiGraph 的有效性和三个 ActiGraph 切点的预测有效性，将 31 名幼儿（17 名男孩；20±4 个月）在日托期间自由玩耍时的加速度计测量值与使用观察系统记录儿童体育活动的直接观察 PA（OSRAC-P）进行比较。使用 Pearson 和 Spearman 相关性评估有效性，并使用接收器操作特性曲线（ROC-AUC）下的面积评估预测有效性。
可行性检查表明，在工作日平均注册时间为 564±62 分钟，周末为 595±83 分钟的情况下，可以包括 30 名幼儿（63.8%）的加速度计测量值。根据父母的报告，83%的人认为佩戴加速度计“不令人不快且不愉快”，没有一个人认为“不愉快”。有效性评估表明，平均 ActiGraph 活动计数与平均 OSRAC-P 活动强度显著正相关（r=0.66；p<0.001；n=31）。此外，在每个观察间隔期间，ActiGraph 活动计数与 OSRAC-P 活动强度水平之间的相关性显著为正（ρ=0.52；p<0.001；n=4218）。最后，三个久坐不动的切点表现出较差到尚可的分类准确性（ROC-AUC：0.56 至 0.71），而三个轻度 PA（ROC-AUC：0.51 至 0.62）和三个中度至剧烈 PA 切点（ROC-AUC：0.53 至 0.57）分别在检测久坐行为、轻度 PA 和中度至剧烈 PA 方面表现出较差的分类准确性。
本研究结果表明，ActiGraph 加速度计测量在量化幼儿 PA 方面是可行且有效的。然而，需要进一步的研究来使用加速度计准确识别幼儿的 PA 强度。
