Cutpoint-free accelerometer metrics to assess children’s physical activity: an example using the school day

Stuart J. Fairclough, Alex Rowlands, SARAH TAYLOR, Lynne Boddy

Research output: Contribution to journalArticle

Abstract

The aims were to (a) investigate associations between a novel accelerometer metric: the minimum acceleration value above which the most active 30‐minutes were accumulated during the school day (M30ACC), and health indicators, and (b) demonstrate that applying an equivalent cut‐point to the M30ACC metric gives comparable prevalence results as a moderate‐to‐vigorous physical activity (MVPA) cut‐point approach. Two hundred and ninety‐six children (age 9‐10‐years) wore wrist‐mounted accelerometers for 7‐days. School day MVPA and M30ACC were calculated. Body mass index (BMI), waist‐to‐height ratio (WHtR), and cardiorespiratory fitness (CRF) were also measured. Mixed linear models investigated associations between M30ACC and health indicators. Agreement between ranked MVPA and M30ACC values was assessed using percent agreement, kappa, sensitivity, and specificity statistics. M30ACC thresholds associated with health indicators were 213 mg (BMI), 206 mg (WHtR), and 269 mg (CRF) for girls. The equivalent values for boys were 234 mg (BMI), 230 mg (WHtR), and 327 mg (CRF). Less than half of girls and 75% of boys accumulated 30 minutes of school day MVPA. Just <50% of girls and >80% of boys had M30ACC values ≥200 mg, which is equivalent to brisk walking. Agreement between MVPA and M30ACC tertiles was high, reflected by the sensitivity and specificity values of >90%. Results demonstrate the utility of M30ACC as a PA metric that is not heavily influenced by researcher decisions. M30ACC has potential as an accelerometer‐specific metric for generating PA guidelines related to health indicators and easily understood forms of activity such as brisk walking.
Original languageEnglish
JournalScandinavian Journal of Medicine and Science in Sports
Early online date8 Oct 2019
DOIs
Publication statusPublished - 22 Oct 2019

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Exercise
Body Mass Index
Health
Walking
Sensitivity and Specificity
Linear Models
Research Personnel
Guidelines
Cardiorespiratory Fitness

Keywords

  • Accelerometer
  • cut-points
  • physical activity
  • guidelines
  • acceleration
  • children
  • school

Cite this

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title = "Cutpoint-free accelerometer metrics to assess children’s physical activity: an example using the school day",
abstract = "The aims were to (a) investigate associations between a novel accelerometer metric: the minimum acceleration value above which the most active 30‐minutes were accumulated during the school day (M30ACC), and health indicators, and (b) demonstrate that applying an equivalent cut‐point to the M30ACC metric gives comparable prevalence results as a moderate‐to‐vigorous physical activity (MVPA) cut‐point approach. Two hundred and ninety‐six children (age 9‐10‐years) wore wrist‐mounted accelerometers for 7‐days. School day MVPA and M30ACC were calculated. Body mass index (BMI), waist‐to‐height ratio (WHtR), and cardiorespiratory fitness (CRF) were also measured. Mixed linear models investigated associations between M30ACC and health indicators. Agreement between ranked MVPA and M30ACC values was assessed using percent agreement, kappa, sensitivity, and specificity statistics. M30ACC thresholds associated with health indicators were 213 mg (BMI), 206 mg (WHtR), and 269 mg (CRF) for girls. The equivalent values for boys were 234 mg (BMI), 230 mg (WHtR), and 327 mg (CRF). Less than half of girls and 75{\%} of boys accumulated 30 minutes of school day MVPA. Just <50{\%} of girls and >80{\%} of boys had M30ACC values ≥200 mg, which is equivalent to brisk walking. Agreement between MVPA and M30ACC tertiles was high, reflected by the sensitivity and specificity values of >90{\%}. Results demonstrate the utility of M30ACC as a PA metric that is not heavily influenced by researcher decisions. M30ACC has potential as an accelerometer‐specific metric for generating PA guidelines related to health indicators and easily understood forms of activity such as brisk walking.",
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author = "Fairclough, {Stuart J.} and Alex Rowlands and SARAH TAYLOR and Lynne Boddy",
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AU - Fairclough, Stuart J.

AU - Rowlands, Alex

AU - TAYLOR, SARAH

AU - Boddy, Lynne

N1 - © 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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N2 - The aims were to (a) investigate associations between a novel accelerometer metric: the minimum acceleration value above which the most active 30‐minutes were accumulated during the school day (M30ACC), and health indicators, and (b) demonstrate that applying an equivalent cut‐point to the M30ACC metric gives comparable prevalence results as a moderate‐to‐vigorous physical activity (MVPA) cut‐point approach. Two hundred and ninety‐six children (age 9‐10‐years) wore wrist‐mounted accelerometers for 7‐days. School day MVPA and M30ACC were calculated. Body mass index (BMI), waist‐to‐height ratio (WHtR), and cardiorespiratory fitness (CRF) were also measured. Mixed linear models investigated associations between M30ACC and health indicators. Agreement between ranked MVPA and M30ACC values was assessed using percent agreement, kappa, sensitivity, and specificity statistics. M30ACC thresholds associated with health indicators were 213 mg (BMI), 206 mg (WHtR), and 269 mg (CRF) for girls. The equivalent values for boys were 234 mg (BMI), 230 mg (WHtR), and 327 mg (CRF). Less than half of girls and 75% of boys accumulated 30 minutes of school day MVPA. Just <50% of girls and >80% of boys had M30ACC values ≥200 mg, which is equivalent to brisk walking. Agreement between MVPA and M30ACC tertiles was high, reflected by the sensitivity and specificity values of >90%. Results demonstrate the utility of M30ACC as a PA metric that is not heavily influenced by researcher decisions. M30ACC has potential as an accelerometer‐specific metric for generating PA guidelines related to health indicators and easily understood forms of activity such as brisk walking.

AB - The aims were to (a) investigate associations between a novel accelerometer metric: the minimum acceleration value above which the most active 30‐minutes were accumulated during the school day (M30ACC), and health indicators, and (b) demonstrate that applying an equivalent cut‐point to the M30ACC metric gives comparable prevalence results as a moderate‐to‐vigorous physical activity (MVPA) cut‐point approach. Two hundred and ninety‐six children (age 9‐10‐years) wore wrist‐mounted accelerometers for 7‐days. School day MVPA and M30ACC were calculated. Body mass index (BMI), waist‐to‐height ratio (WHtR), and cardiorespiratory fitness (CRF) were also measured. Mixed linear models investigated associations between M30ACC and health indicators. Agreement between ranked MVPA and M30ACC values was assessed using percent agreement, kappa, sensitivity, and specificity statistics. M30ACC thresholds associated with health indicators were 213 mg (BMI), 206 mg (WHtR), and 269 mg (CRF) for girls. The equivalent values for boys were 234 mg (BMI), 230 mg (WHtR), and 327 mg (CRF). Less than half of girls and 75% of boys accumulated 30 minutes of school day MVPA. Just <50% of girls and >80% of boys had M30ACC values ≥200 mg, which is equivalent to brisk walking. Agreement between MVPA and M30ACC tertiles was high, reflected by the sensitivity and specificity values of >90%. Results demonstrate the utility of M30ACC as a PA metric that is not heavily influenced by researcher decisions. M30ACC has potential as an accelerometer‐specific metric for generating PA guidelines related to health indicators and easily understood forms of activity such as brisk walking.

KW - Accelerometer

KW - cut-points

KW - physical activity

KW - guidelines

KW - acceleration

KW - children

KW - school

UR - http://www.mendeley.com/research/cutpointfree-accelerometer-metrics-assess-childrens-physical-activity-example-using-school-day

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JO - Scandinavian Journal of Medicine and Science in Sports

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SN - 0905-7188

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