title: Criterion validity of the International Physical Activity Questionnaire Short Form (IPAQ-SF) for use in patients with rheumatoid arthritis: comparison with the SenseWear Armband.
abstract: OBJECTIVE
  The International Physical Activity Questionnaire Short Form (IPAQ-SF) is a self-report questionnaire commonly used in patients with rheumatoid arthritis (RA) to measure physical activity. However, despite its frequent use in patients with RA, its validity has not been ascertained in this population. The aim of this study was to examine the criterion validity of energy expenditure from physical activity recorded with the IPAQ-SF in patients with RA compared with the objective criterion measure, the SenseWear Armband (SWA) which has been validated previously in this population.
  
  
  METHODS
  Cross-sectional criterion validation study.
  
  
  METHODS
  Regional hospital outpatient setting.
  
  
  METHODS
  Twenty-two patients with RA attending outpatient rheumatology clinics.
  
  
  METHODS
  Subjects wore an SWA for 7 full consecutive days and completed the IPAQ-SF.
  
  
  METHODS
  Energy expenditure from physical activity recorded by the SWA and the IPAQ-SF.
  
  
  RESULTS
  Energy expenditure from physical activity recorded by the IPAQ-SF and the SWA showed a small, non-significant correlation (r=0.407, P=0.60). The IPAQ-SF underestimated energy expenditure from physical activity by 41% compared with the SWA. This was corroborated using Bland and Altman plots, as the IPAQ-SF was found to overestimate energy expenditure from physical activity in nine of the 22 individuals, and underestimate energy expenditure from physical activity in the remaining 13 individuals.
  
  
  CONCLUSIONS
  The IPAQ-SF has limited use as an accurate and absolute measure for estimating energy expenditure from physical activity in patients with RA.
authors.affiliation: Department of Clinical Therapies, University of Limerick, Ireland; Department of Medicine, National University of Ireland, Galway, Ireland. Electronic address: marie.m.tierney@nuigalway.ie.
authors.forename: M
authors.initials: M
authors.lastname: Tierney
authors.affiliation: Department of Rheumatology, Mid-Western Regional Hospitals, Limerick, Ireland; Graduate Entry Medical School, University of Limerick, Limerick, Ireland.
authors.forename: A
authors.initials: A
authors.lastname: Fraser
authors.affiliation: Department of Clinical Therapies, University of Limerick, Ireland.
authors.forename: N
authors.initials: N
authors.lastname: Kennedy
mesh_terms: D056044:Actigraphy / Q000379:methods; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000503:physiopathology* / Q000534:rehabilitation*; D003430:Cross-Sectional Studies; D003625:Data Collection / Q000379:methods*; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D026741:Physical Therapy Modalities; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards
keywords: Arthritis; Physical activity; Questionnaires; Rheumatoid; Validation studies