Validity, practical utility, and reliability of the activPAL in preschool children

Davies, G., Reilly, J., McGowan, A., Dall, P., Granat, M. and Paton, J. (2012) Validity, practical utility, and reliability of the activPAL in preschool children. Medicine and Science in Sports and Exercise, 44(4), pp. 761-768. (doi: 10.1249/MSS.0b013e31823b1dc7)

Abstract

<p>Purpose: With the increasing global prevalence of childhood obesity, it is important to have appropriate measurement tools for investigating factors (e.g. sedentary time) contributing to positive energy balance in early childhood. For pre-school children, single unit monitors such as the activPALTM are promising. However, validation is required as activity patterns differ from adults.</p> <p>Methods: Thirty pre-school children participated in a validation study. Children were videoed for one hour undertaking usual nursery activity while wearing an activPALTM. Video (criterion method) was analyzed on a second-by-second basis to categorise posture and activity. This was compared with the corresponding activPALTM output. In a subsequent sub-study investigating practical utility and reliability, 20 children wore an activPALTM for seven consecutive 24-hour periods.</p> <p>Results: A total of 97,750 seconds of direct observation from 30 children were categorized as sit/lie (46%), stand (35%), walk (16%); with 3% of time in nonsit/lie/upright postures (e.g. crawl/crouch/kneel-up). Sensitivity for the overall total time matched seconds detected as activPALTM ‘sit/lie’ was 86.7%, specificity 97.1%, and positive predictive value (PPV) 96.3%. For individual children, the median (interquartile range) sensitivity for activPALTM sit/lie was 92.8% (76.1-97.4), specificity 97.3% (94.9-99.2), PPV 97.0% (91.5-99.1). The activPALTM underestimated total time spent sitting (mean difference -4.4%, p<0.01), and overestimated time standing (mean difference 7.1%, p<0.01). There was no difference in overall % time categorised as ‘walk’ (p=0.2). The monitors were well tolerated by children during a seven day period of free-living activity. In the reliability study, at least five days of monitoring were required to obtain an intraclass correlation coefficient of ≥0.8 for time spent sit/lie according to activPALTM output.</p> <p>Conclusion: The activPAL had acceptable validity, practical utility, and reliability for the measurement of posture and activity during freeliving activities in pre-school children.</p>

• Item Type: Articles
• Additional Information: This is a non-final version of an article published in final form in Medicine and Science in Sports and Exercise 44(4):761-768, DOI: 10.1249/MSS.0b013e31823b1dc7.
• Keywords: activity monitoring, posture, child, validation
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Reilly, Prof John and Paton, Dr James
• Authors: Davies, G., Reilly, J., McGowan, A., Dall, P., Granat, M., and Paton, J.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing > Clinical Specialities
• Journal Name: Medicine and Science in Sports and Exercise
• Publisher: Lippincott, Williams & Wilkins on behalf of American College of Sports Medicine
• ISSN: 0195-9131
• ISSN (Online): 1530-0315
• Published Online: 03 October 2011
• Copyright Holders: Copyright © 2011 American College of Sports Medicine
• First Published: First published in Medicine and Science in Sports and Exercise 44(4):761-768
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher