title: Rasch analyses of the wheelchair use confidence scale.
abstract: OBJECTIVE
  To compare the functioning of the 101-point response format of the Wheelchair Use Confidence Scale (WheelCon) with shortened 11-point formats, and to evaluate the scale's measurement properties using principal components and Rasch analyses.
  
  
  METHODS
  Secondary analysis of cross-sectional data.
  
  
  METHODS
  Community.
  
  
  METHODS
  Volunteer participants were manual wheelchair users (N=220) ≥19 years of age, with ≥6 months' experience with daily wheelchair use and no cognitive impairment.
  
  
  METHODS
  None.
  
  
  METHODS
  65-item WheelCon.
  
  
  RESULTS
  The 11-point response format outperformed the original 101-point format. Principal component analyses confirmed the presence of 2 dimensions: mobility efficacy and self-management efficacy. Thirteen items in the mobility efficacy subscale and 8 items in the self-management efficacy subscale fit the Rasch Rating Scale model. Five items misfit the model developed using the 21 items from both subscales. In each of the 13- and 8-item subscales, and the 21-item short form, the 2 lowest and highest scores had internal consistency reliability estimates <.70; all other scores had reliability estimates >.70.
  
  
  CONCLUSIONS
  The WheelCon is composed of 2 dimensions. The recoded measurements using a 0-to-10 response scale from the 13-item mobility and 8-item self-management efficacy subscales have good reliability, as do the measurements from the 21-item WheelCon Short Form. The use of the subscales, the short form, or both, depends on the context in which they are being considered. Research to establish the reliability and validity of the measurements using the 0-to-10 response format is warranted.
authors.affiliation: Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Rehabilitation Research Program, Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada.
authors.forename: Brodie M
authors.initials: BM
authors.lastname: Sakakibara
authors.affiliation: Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada; Rehabilitation Research Program, Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada; Department of Occupational Sciences and Occupational Therapy, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada. Electronic address: bill.miller@ubc.ca.
authors.forename: William C
authors.initials: WC
authors.lastname: Miller
authors.affiliation: School of Rehabilitation, Faculty of Medicine, University of Montreal, Montréal, Québec, Canada.
authors.forename: Paula W
authors.initials: PW
authors.lastname: Rushton
mesh_terms: D003430:Cross-Sectional Studies; D006233:Persons with Disabilities; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D025341:Principal Component Analysis; D011594:Psychometrics / Q000379:methods; D015203:Reproducibility of Results; D020377:Self Efficacy; D011795:Surveys and Questionnaires; D014910:Wheelchairs
keywords: Factor analysis; Outcome assessment (health care); Psychometrics; Rehabilitation; Self efficacy; Wheelchairs