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Title: Calibration and validation of the ActiGraph GT3X+ in 2-3 year olds
Authors: Costa, Silvia
Barber, Sally E.
Cameron, Noel
Clemes, Stacy A.
Keywords: Accelerometer
Physical activity
Sedentary behaviour
Issue Date: 2014
Publisher: Elsevier Ltd / © Sports Medicine Australia
Citation: COSTA, S. ... et al, 2014. Calibration and validation of the ActiGraph GT3X+ in 2-3 year olds. Journal of Science and Medicine in Sport, 17 (6), pp. 617 - 622.
Abstract: Objectives: To calibrate and validate the ActiGraph GT3X+ to measure sedentary behaviour and physical activity in 2-3 year olds, using 5-s epochs; and to compare the predictive validity of the resulting cut-points with that of NHANES', Trost's, and Pate's 15-s cut-points. Design: Cross-sectional study. Methods: Eighteen children (2.86 ± 0.60 years) wore an ActiGraph GT3X+ during video-recorded semi-structured calibration activity sessions. Activity was coded following Children's Activity Rating Scale. Receiver Operating Characteristic analysis was used to derive Axis1 and vector magnitude cut-points for sedentary behaviour and moderate-to-vigorous physical activity at 5-s epochs. Agreement with Children's Activity Rating Scale was assessed with Cohen's kappa, Lin's concordance, and Bland-Altman plots. Predictive validity of all cut-points was assessed in an independent sample of 20 children (2.99 ± 0.48 years) video-recorded during free-play, using the same procedures as the calibration phase. Results: During calibration, vector magnitude cut-points (sedentary behaviour. ≤. 96.12. counts; moderate-to-vigorous physical activity. ≥. 361.94. counts) showed slightly better classification agreement with Children's Activity Rating Scale than Axis1 cut-points (sedentary behaviour. ≤. 5. counts; moderate-to-vigorous physical activity. ≥. 165. counts), but the latter showed the lowest bias in estimated sedentary behaviour and moderate-to-vigorous physical activity time. In the validation sample, 5-s Axis1 cut-points showed the best predictive validity and lowest mean differences of all cut-points between predicted and observed sedentary behaviour (-2.31%), light physical activity (-24.40%), and total physical activity time (-0.95%). Moderate-to-vigorous physical activity time was significantly overestimated by all cut-points (128.33-184.17%). Conclusions: Because moderate-to-vigorous physical activity was highly overestimated, using only the 5-s Axis1 sedentary behaviour cut-point to distinguish sedentary behaviour from total physical activity is advised. The high accuracy indicates that these cut-points are useful for epidemiological studies involving the sedentary behaviour and physical activity of 2-3 year olds.
Description: This article is closed access.
Sponsor: The first author was the recipient of a studentship from the School of Sport, Exercise and Health Sciences, Loughborough University. This paper presents independent research commissioned by the National Institute for Health Research (NIHR) under the Collaborations for Leadership in Applied Health Research and Care (CLAHRC) programme for Leeds, York and Bradford.
Version: Published
DOI: 10.1016/j.jsams.2013.11.005
URI: https://dspace.lboro.ac.uk/2134/16663
Publisher Link: http://dx.doi.org/10.1016/j.jsams.2013.11.005
ISSN: 1440-2440
Appears in Collections:Closed Access (Sport, Exercise and Health Sciences)

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