Cover Image

Is missing geographic positioning system data in accelerometry studies a problem, and is imputation the solution?

Kristin Meseck, Marta M. Jankowska, Jasper Schipperijn, Loki Natarajan, Suneeta Godbole, Jordan Carlson, Michelle Takemoto, Katie Crist, Jacqueline Kerr
  • Kristin Meseck
    Department of Family Medicine and Public Health, University of California, La Jolla, CA, United States | kmeseck@ucsd.edu
  • Marta M. Jankowska
    Department of Family Medicine and Public Health, University of California, La Jolla, CA, United States
  • Jasper Schipperijn
    Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
  • Loki Natarajan
    Department of Family Medicine and Public Health, University of California, La Jolla, CA, United States
  • Suneeta Godbole
    Department of Family Medicine and Public Health, University of California, La Jolla, CA, United States
  • Jordan Carlson
    Center for Children's Healthy Lifestyles and Nutrition, Children’s Mercy Hospital-University of Missouri, Kansas City, MO, United States
  • Michelle Takemoto
    Department of Family Medicine and Public Health, University of California, La Jolla, CA, United States
  • Katie Crist
    Department of Family Medicine and Public Health, University of California, La Jolla, CA, United States
  • Jacqueline Kerr
    Department of Family Medicine and Public Health, University of California, La Jolla, CA, United States

Abstract

The main purpose of the present study was to assess the impact of global positioning system (GPS) signal lapse on physical activity analyses, discover any existing associations between missing GPS data and environmental and demographics attributes, and to determine whether imputation is an accurate and viable method for correcting GPS data loss. Accelerometer and GPS data of 782 participants from 8 studies were pooled to represent a range of lifestyles and interactions with the built environment. Periods of GPS signal lapse were identified and extracted. Generalised linear mixed models were run with the number of lapses and the length of lapses as outcomes. The signal lapses were imputed using a simple ruleset, and imputation was validated against person-worn camera imagery. A final generalised linear mixed model was used to identify the difference between the amount of GPS minutes pre- and post-imputation for the activity categories of sedentary, light, and moderate-to-vigorous physical activity. Over 17% of the dataset was comprised of GPS data lapses. No strong associations were found between increasing lapse length and number of lapses and the demographic and built environment variables. A significant difference was found between the pre- and postimputation minutes for each activity category. No demographic or environmental bias was found for length or number of lapses, but imputation of GPS data may make a significant difference for inclusion of physical activity data that occurred during a lapse. Imputing GPS data lapses is a viable technique for returning spatial context to accelerometer data and improving the completeness of the dataset.

Keywords

GPS; GIS; Missing data; Imputation; Accelerometer

Full Text:

PDF
HTML
Submitted: 2015-07-30 18:52:56
Published: 2016-05-31 15:17:11
Search for citations in Google Scholar
Related articles: Google Scholar
Abstract views:
618

Views:
PDF
402
HTML
308

Article Metrics

Metrics Loading ...

Metrics powered by PLOS ALM


Copyright (c) 2016 Kristin Meseck, Marta M. Jankowska, Jasper Schipperijn, Loki Natarajan, Suneeta Godbole, Jordan Carlson, Michelle Takemoto, Katie Crist, Jacqueline Kerr

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
 
© PAGEPress 2008-2017     -     PAGEPress is a registered trademark property of PAGEPress srl, Italy.     -     VAT: IT02125780185