title: Validation of the SQUASH Physical Activity Questionnaire in a Multi-Ethnic Population: The HELIUS Study.
abstract: OBJECTIVE
  To investigate the reliability and validity of the SQUASH physical activity (PA) questionnaire in a multi-ethnic population living in the Netherlands.
  
  
  METHODS
  We included participants from the HELIUS study, a population-based cohort study. In this study we included Dutch (n = 114), Turkish (n = 88), Moroccan (n = 74), South-Asian Surinamese (n = 98) and African Surinamese (n = 91) adults, aged 18-70 years. The SQUASH was self-administered twice to assess test-re-test reliability (mean interval 6-7 weeks) and participants wore an accelerometer and heart rate monitor (Actiheart) to enable assessment of construct validity.
  
  
  RESULTS
  We observed low test-re-test reliability; Intra class correlation coefficients ranged from low (0.05 for moderate/high intensity PA in African Surinamese women) to acceptable (0.78 for light intensity PA in Moroccan women). The discrepancy between self-reported and measured PA differed on the basis of the intensity of activity: self-reported light intensity PA was lower than measured but self-reported moderate/high intensity PA was higher than measured, with wide limits of agreement. The discrepancy between questionnaire and Actiheart measures of moderate intensity PA did not differ between ethnic minority and Dutch participants with correction for relevant confounders. Additionally, the SQUASH overestimated the number of participants meeting the Dutch PA norm; Cohen's kappas for the agreement were poor, the highest being 0.30 in Dutch women.
  
  
  CONCLUSIONS
  We found considerable variation in the test-re-test reliability and validity of self-reported PA with no consistency based on ethnic origin. Our findings imply that the SQUASH does not provide a valid basis for comparison of PA between ethnic groups.
authors: Department of Public Health, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors: M
authors: http://orcid.org/0000-0002-0419-5816
authors: M
authors: Nicolaou
authors: Department of Public Health, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors: M G J
authors: MG
authors: Gademan
authors: Department of Public Health, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors: M B
authors: MB
authors: Snijder
authors: Education of Physical Therapy, Amsterdam School of Health Professions (ASHP), University of Applied Sciences, Amsterdam, The Netherlands.|Department of Rehabilitation, Academic Medical Center (AMC), Amsterdam, The Netherlands.
authors: R H H
authors: RH
authors: Engelbert
authors: Department of Epidemiology and Health Promotion, Public Health Service of Amsterdam, Amsterdam, The Netherlands.
authors: H
authors: H
authors: Dijkshoorn
authors: Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands.
authors: C B
authors: CB
authors: Terwee
authors: Department of Public Health, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors: K
authors: K
authors: Stronks
mesh_terms: D061725:Accelerometry; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005006:Ethnicity / Q000145:classification* / Q000706:statistics & numerical data; D015444:Exercise / Q000502:physiology*; D005260:Female; D000070276:Heart Rate Determination; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000208:ethnology; D015203:Reproducibility of Results; D057566:Self Report; D055815:Young Adult