title: Measurement properties of physical function scales validated for use in patients with rheumatoid arthritis: a systematic review of the literature.
abstract: BACKGROUND
  The aim of this study was to systematically review the content validity and measurement properties of all physical function (PF) scales which are currently validated for use with patients with rheumatoid arthritis (RA).
  
  
  METHODS
  Systematic literature searches were performed in the Scopus and PubMed databases to identify articles on the development or psychometric evaluation of PF scales for patients with RA. The content validity of included scales was evaluated by linking their items to the International Classification of Functioning Disability and Health (ICF). Furthermore, available evidence of the reliability, validity, responsiveness, and interpretability of the included scales was rated according to published quality criteria.
  
  
  RESULTS
  The search identified 26 questionnaires with PF scales. Ten questionnaires were rated to have adequate content validity. Construct validity, internal consistency, test-retest reliability and responsiveness was rated favourably for respectively 15, 11, 5, and 6 of the investigated scales. Information about the absolute measurement error and minimal important change scores were rarely reported.
  
  
  CONCLUSIONS
  Based on this literature review, the disease-specificHAQ and the generic SF-36 can currently be most confidently recommended to measure PF in RA for most research purposes. The HAQ, however, was frequently associated with considerable ceiling effects while the SF-36 has limited content coverage. Alternative scales that might be better suited for specific research purposes are identified along with future directions for research.
authors: Arthritis Center Twente, University of Twente, Department of Psychology, Health and Technology, Enschede, The Netherlands. A.H.OudeVoshaar@utwente.nl
authors: Martijn A H
authors: MA
authors: Oude Voshaar
authors: Peter M
authors: PM
authors: ten Klooster
authors: Erik
authors: E
authors: Taal
authors: Mart A F J
authors: MA
authors: van de Laar
mesh_terms: D001172:Arthritis, Rheumatoid / Q000503:physiopathology*; D004185:Disability Evaluation; D006801:Humans; D011594:Psychometrics; D011788:Quality of Life; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires