Equating accelerometer estimates among youth: The Rosetta Stone 2
Equating accelerometer estimates among youth: The Rosetta Stone 2
复制标题
DOI:
10.1016/j.jsams.2015.02.006
复制
发表时间:
2016-03-01
影响因子:
4
通讯作者:
van sluijs, Esther M. F.
中科院分区:
文献类型:
--
作者:
Brazendale, Keith;Beets, Michael W.;van sluijs, Esther M. F.
Objectives: Different accelerometer cutpoints used by different researchers often yields vastly different estimates of moderate-to-vigorous intensity physical activity (MVPA). This is recognized as cutpoint non-equivalence (CNE), which reduces the ability to accurately compare youth MVPA across studies. The objective of this research is to develop a cutpoint conversion system that standardizes minutes of MVPA for six different sets of published cutpoints.Design: Secondary data analysis.Methods: Data from the International Children's Accelerometer Database (ICAD; Spring 2014) consisting of 43,112 Actigraph accelerometer data files from 21 worldwide studies (children 3-18 years, 61.5% female) were used to develop prediction equations for six sets of published cutpoints. Linear and non-linear modeling, using a leave one out cross-validation technique, was employed to develop equations to convert MVPA from one set of cutpoints into another. Bland Altman plots illustrate the agreement between actual MVPA and predicted MVPA values.Results: Across the total sample, mean MVPA ranged from 29.7 MVPA min d(-1) (Puyau) to 126.1 MVPA min d(-1) (Freedson 3 METs). Across conversion equations, median absolute percent error was 12.6% (range: 1.3 to 30.1) and the proportion of variance explained ranged from 66.7% to 99.8%. Mean difference for the best performing prediction equation (VC from EV) was 0.110 min d(-1) (limits of agreement (LOA), -2.623 to 2.402). The mean difference for the worst performing prediction equation (FR3 from PY) was 34.76 min d(-1) (LOA, -60.392 to 129.910).Conclusions: For six different sets of published cutpoints, the use of this equating system can assist individuals attempting to synthesize the growing body of literature on Actigraph, accelerometry-derived MVPA. (C) 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.