Research Study Abstract

Calibration of the global physical activity questionnaire to Accelerometry measured physical activity and sedentary behavior

  • Published on March 27, 2018

Background
Self-report questionnaires are a valuable method of physical activity measurement in public health research; however, accuracy is often lacking. The purpose of this study is to improve the validity of the Global Physical Activity Questionnaire by calibrating it to 7 days of accelerometer measured physical activity and sedentary behavior.

Methods
Participants (n = 108) wore an ActiGraph GT9X Link on their non-dominant wrist for 7 days. Following the accelerometer wear period, participants completed a telephone Global Physical Activity Questionnaire with a research assistant. Data were split into training and testing samples, and multivariable linear regression models built using functions of the GPAQ self-report data to predict ActiGraph measured physical activity and sedentary behavior. Models were evaluated with the testing sample and an independent validation sample (n = 120) using Mean Squared Prediction Errors.

Results
The prediction models utilized sedentary behavior, and moderate- and vigorous-intensity physical activity self-reported scores from the questionnaire, and participant age. Transformations of each variable, as well as break point analysis were considered. Prediction errors were reduced by 77.7–80.6% for sedentary behavior and 61.3–98.6% for physical activity by using the multivariable linear regression models over raw questionnaire scores.

Conclusions
This research demonstrates the utility of calibrating self-report questionnaire data to objective measures to improve estimates of physical activity and sedentary behavior. It provides an understanding of the divide between objective and subjective measures, and provides a means to utilize the two methods as a unified measure.

Author(s)

  • Kristen M. Metcalf 1
  • Barbara I. Baquero 2
  • Mayra L. Coronado Garcia 3
  • Shelby L. Francis 4
  • Kathleen F. Janz 5
  • Helena H. Laroche 6
  • Daniel K. Sewell 7

Institution(s)

  • 1

    University of Iowa, 102 Field House, Iowa City, IA 52242, USA
  • 2

    University of Iowa, N418 CPHB, Iowa City, IA 52242, USA
  • 3

    University of Iowa, N300 CPHB, Iowa City, IA 52242, USA
  • 4

    University of Iowa, SW34 GH, Iowa City, IA 52242, USA
  • 5

    University of Iowa, E130 Field House, Iowa City, IA 52242, USA
  • 6

    University of Iowa, 280B MRF, Iowa City, IA 52242, USA
  • 7

    University of Iowa, N338 CPHB, Iowa City, IA 52242, USA

Journal

BMC Public Health

Categories

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