Accelerometer-derived physical activity estimation in preschoolers - comparison of cut-point sets incorporating the vector magnitude vs the vertical axis
Accelerometer-derived physical activity estimation in preschoolers - comparison of cut-point sets incorporating the vector magnitude vs the vertical axis
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DOI：
10.1186/s12889-019-6837-7
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发表时间：
2019-05-06
影响因子：
4.5
通讯作者：
Kriemler, Susi
中科院分区：
文献类型：
--
作者：
Leeger-Aschmann, Claudia S.;Schmutz, Einat A.;Kriemler, Susi
actigraph加速度计是一种广泛使用的工具，用于客观测量幼儿的身体活动（PA）行为，并且存在几个经过验证的切点集来估计不同PA强度（久坐时间、轻度PA、中度至剧烈PA）所花费的时间。应用不同的截点集会导致结果产生巨大而有意义的差异。到目前为止，只比较了垂直轴验证的切点集，并且只分析了中度至剧烈PA对时间的影响。方法采用经过验证的具有各自历元长度的切点集范围，对瑞士学龄前儿童健康研究（SPLASHY）的横断面数据进行分析：1)纵轴结合历元长度为15s （VA-15), 2)纵轴结合历元长度为60s (VA-60), 3）矢量幅度结合历元长度为60s （VM-60）。使用ActiGraph加速度计（wGT3X-BT）连续8天测量PA。需要将三天纳入分析（至少两个工作日和一个周末，每天至少记录10小时）。结果445名学龄前儿童（平均年龄3.90.5岁，女孩占46%）具有有效的加速度计测量值。较长的epoch （VA-60 vs VA-15）导致久坐时间（ST）减少2%，轻度PA （LPA）增加18%，中度至剧烈PA （MVPA）减少51%；使用矢量幅度与垂直轴（VM-60 vs VA-60）比较，ST减少34%，LPA增加27%，MVPA增加63%（均p0.001）。比较所有三组切割点，ST范围为4.0至6.2h， LPA范围为5.1至7.6h， MVPA范围为0.8至1.6h。结论在不同PA强度下的估计时间受到切割点集选择的强烈影响。在比较不同的研究时，轴的选择和历元长度都需要考虑，特别是当它们将PA行为与健康联系起来时。儿童执行PA指南的患病率的差异突出了这些发现的相关性。当前对照试验ISRCTN41045021（注册日期：2014年3月21日）。
BackgroundActiGraph accelerometers are a widely used tool to objectively measure physical activity (PA) behavior in young children and several validated cut-point sets exist to estimate time spent in different PA intensities (sedentary time, light PA, moderate-to-vigorous PA). Applying different cut-point sets leads to large and meaningful differences in results. So far, only cut-point sets validated for the vertical axis have been compared and only the influence on time spent in moderate-to-vigorous PA has been analyzed.MethodsA range of validated cut-point sets with their respective epoch length was applied to analyze cross-sectional data of the Swiss Preschoolers' Health Study (SPLASHY): 1) Vertical axis in combination with an epoch length of 15s (VA-15), 2) Vertical axis in combination with an epoch length of 60s (VA-60) and 3) Vector magnitude in combination with an epoch length of 60s (VM-60). PA was measured for eight consecutive days using ActiGraph accelerometers (wGT3X-BT). Three days were required to be included in the analysis (minimum two weekdays and one weekend-day with at least ten hours recording per day).ResultsFour hundred forty-five preschoolers (mean age 3.90.5years; 46% girls) had valid accelerometer measurements. A longer epoch (VA-60 vs VA-15) resulted in 2% less sedentary time (ST), 18% more light PA (LPA) and 51% less moderate-to-vigorous PA (MVPA); using the vector magnitude compared to the vertical axis (VM-60 vs VA-60) resulted in 34% less ST, 27% more LPA and 63% more MVPA (all p0.001). Comparing all three sets of cut-points, ST ranged from 4.0 to 6.2h, LPA from 5.1 to 7.6h and MVPA from 0.8 to 1.6h.ConclusionsEstimated time spent in different PA intensities was strongly influenced by the choice of cut-point sets. Both, axis selection and epoch length need to be considered when comparing different studies especially when they relate PA behavior to health. The differences in the prevalence of children fulfilling PA guidelines highlight the relevance of these findings.Trial registration Current Controlled Trials ISRCTN41045021 (date of registration: 21.03.2014).