title: Measuring participation when combining subjective and objective variables: the development of the Ghent Participation Scale (GPS).
abstract: BACKGROUND
  The ICF reflects a bio-psycho-social paradigm and is increasingly used in outpatients rehabilitation settings. The component of participation is in the ICF the manifestation of a bio-psycho-social reasoning. Different participation measures have already been developed and were operationalized through objective and/or a limited set of subjective variables, but keeping them as separate concepts. There is still need for a generic participation instrument including both objective and all relevant subjective variables resulting in one participation score.
  
  
  OBJECTIVE
  To develop a generic participation measure based on objective and subjective aspects and leading to one final score; the Ghent Participation Scale (GPS). Additionally it was the aim to explore whether the GPS has a good internal validity by means of factorial validity and homogeneity and whether the GPS is feasible and interpretable.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Outpatient rehabilitation centre.
  
  
  METHODS
  One hundred thirty former rehabilitation outpatients with various conditions.
  
  
  METHODS
  Item derivation for the GPS was based on qualitative research. The participants administered the GPS in the third week after discharge from the Ghent University Hospital. An exploratory factor analysis was performed to determine underlying dimensions. Statistical coherence was expressed in both item-total correlations and in Cronbach's α coefficient.
  
  
  RESULTS
  An exploratory factor analysis showed 3 underlying dimensions within the GPS: 1) performing activities according to preferred choices and wishes; 2) social appreciation and acceptance by performing activities; and 3) the need to delegate activities explaining 55.8% of the total variance. The results show a good to strong homogeneity (item-total ranged from 0.58 to 0.80) and a strong internal consistency (Cronbach's α ranged from 0.76-0.92).
  
  
  CONCLUSIONS
  The results of this preliminary validation study suggest that the GPS appears to be a valid measure to rate participation.
  
  
  CONCLUSIONS
  Further research and more and more powerful psychometric models such as Rash Analysis or Item Response models are needed to establish a psychometrically sound instrument.
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Ghent University, Ghent, Belgium - dominique.vandevelde@ugent.be.
authors.forename: Dominique
authors.initials: D
authors.lastname: VAN DE Velde
authors.forename: Piet
authors.initials: P
authors.lastname: Bracke
authors.forename: Geert
authors.initials: G
authors.lastname: VAN Hove
authors.forename: Staffan
authors.initials: S
authors.lastname: Josephsson
authors.forename: Annick
authors.initials: A
authors.lastname: Viaene
authors.forename: Ellen
authors.initials: E
authors.lastname: DE Boever
authors.forename: Pascal
authors.initials: P
authors.lastname: Coorevits
authors.forename: Guy
authors.initials: G
authors.lastname: Vanderstraeten
mesh_terms: D000328:Adult; D000368:Aged; D000553:Ambulatory Care / Q000379:methods; D001530:Belgium; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D006233:Persons with Disabilities / Q000523:psychology* / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010045:Outpatients / Q000706:statistics & numerical data; D010358:Patient Participation / Q000523:psychology* / Q000706:statistics & numerical data; D011594:Psychometrics; D036301:Qualitative Research; D012047:Rehabilitation Centers; D015203:Reproducibility of Results; D012959:Socioeconomic Factors