Dimensionality and Construct Validity of the Fugl-Meyer Assessment of the Upper Extremity
Presented as a poster to the American Occupational Therapy Association Annual Conference. May 13, 2005, Long Beach, CA.
Abstract
Woodbury ML, Velozo CA, Richards LG, Duncan PW, Studenski S, Lai S-M. Dimensionality and construct validity of the Fugl-Meyer Assessment of the upper extremity.
Objective
To investigate the dimensionality and construct validity of the Fugl-Meyer Assessment of the upper extremity by using Rasch analysis.
Design
Secondary analysis of pooled data from 2 existing datasets: a randomized therapeutic exercise clinical trial and a cohort longitudinal study of stroke recovery.
Setting
University research center.
Participants
A total of 512 subjects, ages 69.8±11.1 years, who were 0 to 145 days poststroke.
Interventions
Not applicable.
Main Outcome Measures
Dimensionality was examined with principal components analysis and Rasch item-fit statistics. The Rasch-derived item hierarchy was examined for consistency with the expected course of poststroke upper-extremity recovery suggested by the reflex-hierarchical conceptual model underlying the assessment.
Results
Factor loadings and item infit statistics suggested that the 3 reflex items were empirically disconnected from other assessment items. The reflex items were removed. The modified 30-item assessment showed a unidimensional structure. The Rasch-item-difficulty order was not consistent with the expected item order.
Conclusions
The items testing resting-state reflexes may threaten the assessment’s dimensionality. With reflex items removed, the assessment is a unidimensional measure of volitional movement. The Rasch-generated item-difficulty order challenges the hierarchical structure implied by the instrument’s underlying conceptual framework.
aRehabilitation Outcomes Research Center, Malcolm Randall VA Medical Center, Gainesville FL
bBrain Rehabilitation Research Centers, Malcolm Randall VA Medical Center, Gainesville FL
cDepartment of Occupational Therapy, University of Florida, Gainesville, FL
dRehabilitation Science Doctoral Program, University of Florida, Gainesville, FL
eDepartment of Aging and Geriatric Research, University of Florida, Gainesville, FL
fDivision of Geriatric Medicine, University of Pittsburgh, Pittsburgh, PA
gDepartment of Preventative Medicine, University of Kansas, Kansas City, KS.
Reprint requests to Michelle L. Woodbury, PhD, Dept of Occupational Therapy, College of Public Health and Health Professions, University of Florida, PO Box 100164, Gainesville, FL 32610
Supported by the North Florida/South Georgia Veterans Health System, Gainesville, FL, a National Institutes of Health T-32 Neuromuscular Plasticity Institutional Training Grant Fellowship (grant no. T32HD043730), and the National Institute on Aging, Claude D. Pepper Center Older Americans Center (grant no. 5P60AG14635).
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated.
ABSTRACT