title: Are Self-report Measures Able to Define Individuals as Physically Active or Inactive?
abstract: OBJECTIVE
  Assess the agreement between commonly used self-report methods compared with objectively measured physical activity (PA) in defining the prevalence of individuals compliant with PA recommendations.
  
  
  METHODS
  Time spent in moderate and vigorous PA (MVPA) was measured at two time points in 1713 healthy individuals from nine European countries using individually calibrated combined heart rate and movement sensing. Participants also completed the Recent Physical Activity Questionnaire (RPAQ), short form of the International Physical Activity Questionnaire (IPAQ), and short European Prospective Investigation into Cancer and Nutrition Physical Activity Questionnaire (EPIC-PAQ). Individuals were categorized as active (e.g., reporting ≥150 min of MVPA per week) or inactive, based on the information derived from the different measures. Sensitivity and specificity analyses and Kappa statistics were performed to evaluate the ability of the three PA questionnaires to correctly categorize individuals as active or inactive.
  
  
  RESULTS
  Prevalence estimates of being sufficiently active varied significantly (P for all <0.001) between self-report measures (IPAQ 84.2% [95% confidence interval {CI}, 82.5-85.9], RPAQ 87.6% [95% CI, 85.9-89.1], EPIC-PAQ 39.9% [95% CI, 37.5-42.1] and objective measure 48.5% [95% CI, 41.6-50.9]. All self-report methods showed low or moderate sensitivity (IPAQ 20.0%, RPAQ 18.7%, and EPIC-PAQ 69.8%) to correctly classify inactive people and the agreement between objective and self-reported PA was low (ĸ = 0.07 [95% CI, 0.02-0.12], 0.12 [95% CI, 0.06-0.18], and 0.19 [95% CI, 0.13-0.24] for IPAQ, RPAQ, and EPIC-PAQ, respectively).
  
  
  CONCLUSIONS
  The modest agreement between self-reported and objectively measured PA suggests that population levels of PA derived from self-report should be interpreted cautiously. Implementation of objective measures in large-scale cohort studies and surveillance systems is recommended.
authors: 1Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, NORWAY; 2VU University Medical Center, Department of Public and Occupational Health, EMGO Institute for Health and Care Research, Amsterdam, THE NETHERLANDS; 3TNO Expertise Centre Lifestyle, Leiden, THE NETHERLANDS; 4Body@Work TNO-VUmc, Research Center Physical Activity, Work and Health, Amsterdam, THE NETHERLANDS; 5Department of Physical Education and Sport Sciences, University of Limerick, Limerick, IRELAND; and 6Medical Research Council Epidemiology Unit, University of Cambridge, Cambridge, UNITED KINGDOM.
authors: Jostein
authors: J
authors: Steene-Johannessen
authors: Sigmund A
authors: SA
authors: Anderssen
authors: Hidde P
authors: HP
authors: van der Ploeg
authors: Ingrid J M
authors: IJ
authors: Hendriksen
authors: Alan E
authors: AE
authors: Donnelly
authors: Søren
authors: S
authors: Brage
authors: Ulf
authors: U
authors: Ekelund
mesh_terms: D061725:Accelerometry; D005060:Europe; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D057566:Self Report; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires