Title: Effects of filter choice in GT3X accelerometer assessments of free-living activity
Authors : Wanner, Miriam
Martin, Brian W
Meier, Flurina
Probst-Hensch, Nicole
Kriemler, Susi
Published in : Medicine and science in sports and exercise
Volume(Issue) : 45
Issue : 1
Pages : 170
Pages to: 177
Publisher / Ed. Institution : Lippincott Williams & Wilkins
Issue Date: 1-Jan-2013
License (according to publishing contract) : Licence according to publishing contract
Type of review: Peer review (Publication)
Language : English
Subjects : Actigraph; Sedentary behaviour; Low-frequency extension; Physical activity
Subject (DDC) : 610: Medicine and health
Abstract: Purpose: ActiGraph accelerometers are widely used devices to objectively assess physical activity. The GT3X version has two filter options to be selected before data assessment (normal and low-frequency extension filter option). It is not clear whether the resulting physical activity levels differ depending on the choice of the filter. The aims were to compare GT3X data collected using the different filter options during free-living activities and to establish correction factors if the results were not comparable. Methods: Sixty-five participants of the population-based SAPALDIA-cohort (50.8% women, age range = 40–80 yr) wore two GT3X accelerometers with different filter selections simultaneously during 8 d. Spearman correlations, Wilcoxon rank sum tests, McNemar tests, scatter plots, and Bland–Altman plots were used to compare the data. Correction factors were established using linear regression models. Results: Although Spearman correlations were high (r Q 0.93), there were significant differences in minutes per day between filter options for nonwearing time and time spent in sedentary, light, and moderate-to-vigorous physical activity (all P G 0.001), with more remarkable differences in the lower range of activity (sedentary and light activities). Mean counts per minute and steps per day were significantly higher using the low-frequency extension filter (P G 0.001). Most differences could be resolved using the correction factors. Conclusions: The observed differences are especially important when research is focusing on sedentary and light activities. In future studies, it is important to carefully evaluate the suitable filter option and to specify the filter choice in publications. The correction factors can be used to make data assessed using the lowfrequency extension filter comparable to data assessed using the normal filter option.
Departement: School of Management and Law
Organisational Unit: Winterthur Institute of Health Economics (WIG)
Publication type: Article in scientific Journal
DOI : 10.1249/MSS.0b013e31826c2cf1
ISSN: 1530-0315
0195-9131
URI: https://digitalcollection.zhaw.ch/handle/11475/16262
Appears in Collections:Publikationen School of Management and Law

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