A new 2-regression model for the Actical accelerometer
A new 2-regression model for the Actical accelerometer
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DOI：
10.1136/bjsm.2006.033399
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发表时间：
2008-03-01
影响因子：
18.4
通讯作者：
Bassett, D. R., Jr.
中科院分区：
文献类型：
--
作者：
Crouter, S. E.;Bassett, D. R., Jr.
目的：本研究的目的是开发一种将实际活动计数与 MET 相关联的新 2 回归模型。方法：48 名参与者（平均 (SD) 年龄 35 (11.4) 岁）进行了 10 分钟的各种活动，范围从久坐行为到剧烈的体力活动。 18 项活动被分为三个例程，每个例程由 20 个人执行。随机选择了 45 个例程来开发新的 2 回归模型，并使用 15 项测试来交叉验证新的 2 回归模型并将其与现有方程进行比较。在每次训练中，参与者在臀部佩戴一个 Actical 加速度计，并通过便携式代谢系统同时测量耗氧量。每分钟计算四个连续 15 秒时期的变异系数 (CV)。对于每项活动，计算第 4-9 分钟的平均 CV 和计数 min(-1)。如果 CV 为 13%，则使用生活方式/休闲时间体力活动回归。结果：指数回归线（R-2 = 0.912；估计标准误差 (SEE)= 0.149）用于 CV（13%）的活动，三次回归线（R-2 = 0.884，SEE = 0.804）用于 CV > 13% 的活动。交叉验证组的平均估计， 使用具有不活动阈值的新 2 回归模型，除骑自行车外（p < 0.05）外，每项活动的测量 MET 均在 0.56 MET 范围内（p >= 0.05）。结论：对于检查的大多数活动，新 2 回归模型比当前可用的 Actical 加速度计方程更准确地预测 MET。
Objective: The objective of this study was to develop a new 2-regression model relating Actical activity counts to METs.Methods: Forty-eight participants (mean (SD) age 35 (11.4) years) performed 10 min bouts of various activities ranging from sedentary behaviours to vigorous physical activities. Eighteen activities were split into three routines with each routine being performed by 20 individuals. Forty-five routines were randomly selected for the development of a new 2-regression model and 15 tests were used to cross-validate the new 2-regression model and compare it against existing equations. During each routine, the participant wore an Actical accelerometer on the hip and oxygen consumption was simultaneously measured by a portable metabolic system. The coefficient of variation (CV) of four consecutive 15 s epochs was calculated for each minute. For each activity, the average CV and the counts min(-1) were calculated for minutes 4-9. If the CV was 13% a lifestyle/leisure time physical activity regression was used.Results: An exponential regression line (R-2 = 0.912; standard error of the estimate (SEE)= 0.149) was used for activities with a CV(13%, and a cubic regression line (R-2 = 0.884, SEE = 0.804) was used for activities with a CV > 13%. In the cross-validation group the mean estimates, using the new 2-regression model with an inactivity threshold, were within 0.56 METs of measured METs for each of the activities performed (p >= 0.05), except cycling (p < 0.05).Conclusion: For most activities examined the new 2-regression model predicted METs more accurately than currently available equations for the Actical accelerometer.