Citation

Miller KJ, Pollock CL, Brouwer B, Garland SJ. Phys. Ther. 2016; 96(10): 1648-1657.

Affiliation

S.J. Garland, PT, PhD, Department of Physical Therapy, The University of British Columbia.

Copyright

(Copyright © 2016, American Physical Therapy Association)

DOI

10.2522/ptj.20150423

PMID

27081206

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: 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. CB&M data were collected at 3 time-points: discharge from inpatient rehabilitation, 6 and 12-months post-discharge (total 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 and One-way Repeated Measures ANOVA.

RESULTS: The CB&M was primarily linked to closed body transport task demands. Significant item-trait interaction (p<0.0005), disordered scoring hierarchies and multi-dimensionality 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 (p=.200) with no item response bias, acceptable targeting (13% floor and 0% ceiling effects) and moderate-strong sensitivity to change at 6-months (SRM.63; 95%CI -1.523,-.142; p=.019) and 12-months post-discharge (SRM.73; 95%CI -2.318,-760; p<.0005). LIMITATIONS: Findings are limited to a modest sized sample of individuals with mild-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 post-stroke. Future studies are recommended in a larger sample to validate and further refine the scale for use in this clinical population.

© 2016 American Physical Therapy Association.

Language: en