title: Educational differences in the validity of self-reported physical activity.
abstract: BACKGROUND
  The assessment of physical activity for surveillance or population based studies is usually done with self-report questionnaires. However, bias in self-reported physical activity may be greater in lower educated than in higher educated populations. The aim of the present study is to describe educational differences in the validity of self-reported physical activity.
  
  
  METHODS
  We included 196 healthy adults (age 57 ± 15.4, of whom 17% low, 24% medium and 59% high educated). Criterion validity of an adapted International Physical Activity Questionnaire was assessed against the ActiGraph GT3X+ accelerometer.
  
  
  RESULTS
  While criterion validity of self-reported physical activity was low to moderate in the total sample (Spearman rho ranged from 0.16 to 0.27, depending on the variables used), the validity in lower educated respondents was poor (-0.07 to 0.05).
  
  
  CONCLUSIONS
  The results confirm the hypothesis that self-report physical activity questionnaires are less valid in lower educated populations.
authors: Department of Epidemiology and Biostatics, EMGO Institute for Health and Care Research, VU University Medical Center Amsterdam, De Boelelaan 1089a, 1081, HV, Amsterdam, The Netherlands. a.winckers@gmail.com.
authors: Annemarie N E
authors: AN
authors: Winckers
authors: Department of Epidemiology and Biostatics, EMGO Institute for Health and Care Research, VU University Medical Center Amsterdam, De Boelelaan 1089a, 1081, HV, Amsterdam, The Netherlands. j.mackenbach@vumc.nl.
authors: Joreintje D
authors: JD
authors: Mackenbach
authors: Department of Movement and Sport Sciences, Ghent University, Ghent, Belgium. Sofie.Compernolle@UGent.be.
authors: Sofie
authors: S
authors: Compernolle
authors: Department of Public Health, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands. m.nicolaou@amc.uva.nl.
authors: Mary
authors: M
authors: Nicolaou
authors: Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Center Amsterdam, Amsterdam, The Netherlands. hp.vanderploeg@vumc.nl.
authors: Hidde P
authors: HP
authors: van der Ploeg
authors: Department of Movement and Sport Sciences, Ghent University, Ghent, Belgium. Ilse.DeBourdeaudhuij@UGent.be.
authors: Ilse
authors: I
authors: De Bourdeaudhuij
authors: Department of Epidemiology and Biostatics, EMGO Institute for Health and Care Research, VU University Medical Center Amsterdam, De Boelelaan 1089a, 1081, HV, Amsterdam, The Netherlands. j.brug@vumc.nl.
authors: Johannes
authors: J
authors: Brug
authors: Department of Epidemiology and Biostatics, EMGO Institute for Health and Care Research, VU University Medical Center Amsterdam, De Boelelaan 1089a, 1081, HV, Amsterdam, The Netherlands. j.lakerveld@vumc.nl.
authors: Jeroen
authors: J
authors: Lakerveld
mesh_terms: D056044:Actigraphy; D000328:Adult; D000368:Aged; D004522:Educational Status; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D015203:Reproducibility of Results; D057566:Self Report; D011795:Surveys and Questionnaires