Research Database

184 results for "Validation"

Reliable assessment of physical activity in disease: an update on activity monitors

  • Published on Sept. 2014

Purpose of Review: Physical activity is the main determinant of variability of individual energy expenditure. Reliable assessment of the activity level of an individual provides information on energy requirement and vital health. Here, evidence is presented on the validity of methods to assess physical activity as applied in health and ...


Validity of the Global Physical Activity Questionnaire (GPAQ) in assessing levels and change in moderate-vigorous physical activity and sedentary behaviour

  • Published on Dec. 10, 2014

Background: easible, cost-effective instruments are required for the surveillance of moderate-to-vigorous physical activity (MVPA) and sedentary behaviour (SB) and to assess the effects of interventions. However, the evidence base for the validity and reliability of the World Health Organisation-endorsed Global Physical Activity Questionnaire (GPAQ) is limited. We aimed to assess ...


Classification of physical activity intensities using a wrist-worn accelerometer in 8–12-year-old children

  • Published on April 20, 2015

Background: Population-specific accelerometer cut-points are required to accurately determine the accumulation of physical activity of various intensities. Objectives: A calibration study was conducted (i) to determine the cut-points for the ActiGraph GT3X+, non-dominant, wrist-mounted accelerometer in children aged 8–12 years and (ii) to compare classification accuracies among the accelerometer's three ...


Methods to estimate aspects of physical activity and sedentary behavior from high frequency wrist accelerometer measurements

  • Published on June 25, 2015

Abstract: This investigation developed models to estimate aspects of physical activity and sedentary behavior from three-axis high frequency wrist worn accelerometer data. The models were developed and tested on twenty participants (n=10 males, n=10 females, mean age= 24.1, mean BMI = 23.9) who wore an Actigraph GT3X+ accelerometer on their dominant wrist ...


Impact of accelerometer data processing decisions on the sample size, wear time and physical activity level of a large cohort study

  • Published on Nov. 24, 2014

Background: Accelerometers objectively assess physical activity (PA) and are currently used in several large-scale epidemiological studies, but there is no consensus for processing the data. This study compared the impact of wear-time assessment methods and using either vertical (V)-axis or vector magnitude (VM) cut-points on accelerometer output. Methods: Participants (7,650 ...


Subjective and objective levels of physical activity and their association with cardiorespiratory fitness in rheumatoid arthritis patients

  • Published on March 13, 2015

Introduction: The aims of the present study were: (a) to examine the agreement between subjective (assessed via the International Physical Activity Questionnaire; IPAQ) and objective (accelerometry; GT3X) physical activity (PA) levels in patients with rheumatoid arthritis (RA), and (b) to evaluate the associations of RA patients’ subjective and objective ...



Separating Bedtime Rest from Activity Using Waist or Wrist-Worn Accelerometers in Youth

  • Published on April 11, 2014

Abstract: Recent interest in sedentary behavior and technological advances expanded use of watch-size accelerometers for continuous monitoring of physical activity (PA) over extended periods (e.g., 24 h/day for 1 week) in studies conducted in natural living environment. This approach necessitates the development of new methods separating bedtime rest and activity ...


Assessing sleep using hip and wrist actigraphy

  • Published on Jan. 19, 2015

Abstract: Wrist actigraphy is commonly used to measure sleep, and hip actigraphy is commonly used to measure activity. It is unclear whether hip-based actigraphy can be used to measure sleep. This study assessed the validity of wrist actigraphy and hip actigraphy compared to polysomnography (PSG) for the measurement of sleep. 108 ...


Reliability and Validity of the Transport and Physical Activity Questionnaire (TPAQ) for Assessing Physical Activity Behaviour

  • Published on Sept. 12, 2014

Background: No current validated survey instrument allows a comprehensive assessment of both physical activity and travel behaviours for use in interdisciplinary research on walking and cycling. This study reports on the test-retest reliability and validity of physical activity measures in the transport and physical activity questionnaire (TPAQ). Methods: The TPAQ ...