Reliability and validity of a new accelerometer-based device for detecting physical activities and energy expenditure

Yanxiang Yang; Moritz Schumann; Shenglong Le; Shulin Cheng

doi:10.7717/peerj.5775

Reliability and validity of a new accelerometer-based device for detecting physical activities and energy expenditure

PeerJ. 2018 Oct 11:6:e5775. doi: 10.7717/peerj.5775. eCollection 2018.

Authors

Yanxiang Yang¹, Moritz Schumann^{2

3}, Shenglong Le^{1

4}, Shulin Cheng^{1

3

4

5}

Affiliations

¹ Department of Physical Education, Exercise, Health and Technology Center, Shanghai Jiao Tong University, Shanghai, China.
² Institute of Cardiovascular Research and Sport Medicine, Department of Molecular and Cellular Sport Medicine, German Sport University, Cologne, Germany.
³ The Exercise Translational Medicine Center, Shanghai Jiao Tong University, Shanghai, China.
⁴ Unit of Health Sciences, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
⁵ The Key Laboratory of Systems Biomedicine, Ministry of Education, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China.

Abstract

Background: Objective assessments of sedentary behavior and physical activity (PA) by using accelerometer-based wearable devices are ever expanding, given their importance in the global context of health maintenance. This study aimed to determine the reliability and validity of a new accelerometer-based analyzer (Fibion) for detecting different PAs and estimating energy expenditure (EE) during a simulated free-living day.

Methods: The study consisted of two parts: a reliability (n = 18) and a validity (n = 19) test. Reliability was assessed by a 45 min protocol of repeated sitting, standing, and walking (i.e., 3 × 15 min, repeated twice), using both Fibion and ActiGraph. Validity was assessed by a 12 h continuous sequence tasks of different types (sitting, standing, walking, and cycling) and intensities (light [LPA], moderate [MPA], and vigorous [VPA]) of PA. Two Fibion devices were worn on the thigh (FT) and in the pocket (FP), respectively and were compared with criteria measures, such as direct observation (criterion 1) and oxygen consumption by a portable gas analyzer, K4b² (criterion 2).

Results: FT (intra-class correlation coefficients (ICCs): 0.687-0.806) provided similar reliability as the Actigraph (ICCs: 0.661-0.806) for EE estimation. However, the measurement error (ME) of FT compared to the actual time records indicated an underestimation of duration by 5.1 ± 1.2%, 3.8 ± 0.3% and 14.9 ± 2.6% during sitting, walking, and standing, respectively. During the validity test, FT but not FP showed a moderate agreement but lager variance with the criteria (1 and 2) in assessing duration of sitting, long sitting, LPA, MPA, and VPA (p > 0.05, ICCs: 0.071-0.537), as well as for EE estimation of standing, LPA, MPA, and VPA (p > 0.05, ICCs: 0.673-0.894).

Conclusions: FT provided similar reliability to that of the Actigraph. However, low correlations between subsequent measurements of both devices indicated large random MEs, which were somewhat diminished during the simulated 12 h real-life test. Furthermore, FT may accurately determine the types, intensities of PA and EE during prolonged periods with substantial changes in postures, indicating that the location of the accelerometer is essential. Further study with a large cohort is needed to confirm the usability of Fibion, especially for detecting the low-intensity PAs.

Keywords: Activity tracker; Motion; Posture allocation; Sedentary behavior.

Grants and funding

This study was supported by a grant from the Chinese Postdoctoral Science Foundation (2016M590352/OT) and the Shanghai Jiao Tong University Zhiyuan Foundation (Grant CP2014013). There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.