Citation

Matsuda PN, Taylor CS, Shumway-Cook A. Phys. Ther. 2014; 94(7): 996-1004.

Affiliation

P.N. Matsuda, PT, PhD, DPT, Department of Rehabilitation Medicine, Division of Physical Therapy, University of Washington, 1959 NE Pacific St, Box 356490, Seattle, WA 98195 (USA).

Copyright

(Copyright © 2014, American Physical Therapy Association)

DOI

10.2522/ptj.20130294

PMID

24557650

Abstract

BackgroundThe modified Dynamic Gait Index (mDGI) measures the capacity to adapt gait to complex tasks utilizing 8 tasks and 3 facets of performance. The measurement stability of the mDGI in specific diagnostic groups is unknown.ObjectiveThis study examined the psychometric properties of the mDGI in five diagnostic groups.DesignCross Sectional, Descriptive StudyMethods794 participants included: 140 controls, 239 with Stroke, 140 with Vestibular Dysfunction, 100 with Traumatic Brain Injury (TBI), 91 with Gait Abnormality, and 84 with Parkinson's Disease (PD). Differential item functioning analysis (DIF) examined the comparability of scores across diagnosis. Internal consistency was computed using Cronbach's alpha. Factor analysis examined the factor loadings for the three performance facet scores. Minimal Detectable Change (MDC95%) was calculated for each of the groups.ResultsLess than 5% of comparisons demonstrated moderate to large DIF, suggesting that item scores had the same order of difficulty for individuals in all five diagnostic groups. For all five patient groups, 3 factors had Eigen values > 1.0 and explained 80% of the variability in scores, supporting the importance of characterizing mobility performance with respect to Time, Level of Assistance and Gait Pattern.LimitationsThe limitation included uneven sample sizes in the six groups.ConclusionsThe strength of the psychometric properties of the mDGI across the five diagnostic groups further supports the validity and usefulness of scores for clinical and research purposes. In addition, the meaning of a score from the mDGI, whether at the task, performance facet, or total score level, was comparable across five diagnostic groups suggesting that the mDGI measured mobility function independent of medical diagnosis.

Language: en