title: Validation of Web-based physical activity measurement systems using doubly labeled water.
abstract: BACKGROUND
  Online or Web-based measurement systems have been proposed as convenient methods for collecting physical activity data. We developed two Web-based physical activity systems-the 24-hour Physical Activity Record Web (24hPAR WEB) and 7 days Recall Web (7daysRecall WEB).
  
  
  OBJECTIVE
  To examine the validity of two Web-based physical activity measurement systems using the doubly labeled water (DLW) method.
  
  
  METHODS
  We assessed the validity of the 24hPAR WEB and 7daysRecall WEB in 20 individuals, aged 25 to 61 years. The order of email distribution and subsequent completion of the two Web-based measurements systems was randomized. Each measurement tool was used for a week. The participants' activity energy expenditure (AEE) and total energy expenditure (TEE) were assessed over each week using the DLW method and compared with the respective energy expenditures estimated using the Web-based systems.
  
  
  RESULTS
  The mean AEE was 3.90 (SD 1.43) MJ estimated using the 24hPAR WEB and 3.67 (SD 1.48) MJ measured by the DLW method. The Pearson correlation for AEE between the two methods was r = .679 (P < .001). The Bland-Altman 95% limits of agreement ranged from -2.10 to 2.57 MJ between the two methods. The Pearson correlation for TEE between the two methods was r = .874 (P < .001). The mean AEE was 4.29 (SD 1.94) MJ using the 7daysRecall WEB and 3.80 (SD 1.36) MJ by the DLW method. The Pearson correlation for AEE between the two methods was r = .144 (P = .54). The Bland-Altman 95% limits of agreement ranged from -3.83 to 4.81 MJ between the two methods. The Pearson correlation for TEE between the two methods was r = .590 (P = .006). The average input times using terminal devices were 8 minutes and 10 seconds for the 24hPAR WEB and 6 minutes and 38 seconds for the 7daysRecall WEB.
  
  
  CONCLUSIONS
  Both Web-based systems were found to be effective methods for collecting physical activity data and are appropriate for use in epidemiological studies. Because the measurement accuracy of the 24hPAR WEB was moderate to high, it could be suitable for evaluating the effect of interventions on individuals as well as for examining physical activity behavior.
authors.affiliation: Faculty of Sports and Health Science, Fukuoka University, Fukuoka, Japan. hnanba@fukuoka-u.ac.jp
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Namba
authors.forename: Yukio
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Yamada
authors.forename: Satoru
authors.initials: S
authors.lastname: Tokushima
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Hatamoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sagayama
authors.forename: Misaka
authors.initials: M
authors.lastname: Kimura
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Higaki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D000328:Adult; D003903:Deuterium; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D020407:Internet; D008297:Male; D008875:Middle Aged; D009043:Motor Activity
chemical_list: D003903:Deuterium