title: Use of Rasch Analysis to Evaluate and Refine the Community Balance and Mobility Scale for Use in Ambulatory Community-Dwelling Adults Following Stroke.
abstract: BACKGROUND
  The Community Balance and Mobility Scale (CB&M) is increasingly used to evaluate walking balance following stroke.
  
  
  OBJECTIVE
  This study applied Rasch analysis to evaluate and refine the CB&M for use in ambulatory community-dwelling adults following stroke.
  
  
  METHODS
  The CB&M content was linked to task demands and motor skill classifications. Rasch analysis was used to evaluate internal construct validity (structural validity) and refine the CB&M for use with ambulatory community-dwelling adults following stroke. The CB&M data were collected at 3 time points: at discharge from inpatient rehabilitation and at 6 and 12 months postdischarge (N=238). Rasch analysis evaluated scale dimensionality, item and person fit, item response bias, scoring hierarchy, and targeting. Disordered scoring hierarchy was resolved by collapsing scoring categories. Highly correlated and "misfitting" items were removed. Sensitivity to change was evaluated with standardized response means (SRMs) and one-way repeated-measures analysis of variance.
  
  
  RESULTS
  The CB&M was primarily linked to closed body transport task demands. Significant item-trait interaction, disordered scoring hierarchies, and multidimensionality were found. Scoring categories were collapsed in 15/19 items, and 5 misfitting items were removed. The resulting stroke-specific 14-item unidimensional CB&M (CB&MStroke) fit Rasch model expectations, with no item response bias, acceptable targeting (13% floor effects and 0% ceiling effects), and moderate-to-strong sensitivity to change at 6 months postdischarge (SRM=0.63; 95% confidence interval=-1.523, -0.142) and 12 months postdischarge (SRM=0.73; 95% confidence interval=-2.318, -0.760).
  
  
  CONCLUSIONS
  Findings are limited to a modest-sized sample of individuals with mild-to-moderate balance impairment following stroke.
  
  
  CONCLUSIONS
  The CB&MStroke shows promise as a clinical scale for measuring change in walking balance in ambulatory community-dwelling adults poststroke. Future studies are recommended in a larger sample to validate and further refine the scale for use in this clinical population.
authors.affiliation: K.J. Miller, PT, PhD, Department of Physical Therapy, The University of British Columbia, 212 Friedman Bldg, 2177 Wesbrook Mall, Vancouver, British Columbia, Canada DV6T 1Z3. kimberly_miller@sfu.ca.
authors.forename: Kimberly J
authors.initials: KJ
authors.lastname: Miller
authors.affiliation: C.L. Pollock, PT, PhD, Department of Rehabilitation Sciences, The University of British Columbia.
authors.forename: Courtney L
authors.initials: CL
authors.lastname: Pollock
authors.affiliation: B. Brouwer, PhD, School of Rehabilitation Therapy, Queen's University, Kingston, Ontario, Canada.
authors.forename: Brenda
authors.initials: B
authors.lastname: Brouwer
authors.affiliation: S.J. Garland, PT, PhD, Department of Physical Therapy, The University of British Columbia.
authors.forename: S Jayne
authors.initials: SJ
authors.lastname: Garland
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D057187:Independent Living; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D011594:Psychometrics; D015203:Reproducibility of Results; D020521:Stroke / Q000503:physiopathology*; D000071939:Stroke Rehabilitation