Article

Tools chosen to measure poststroke upper-extremity rehabilitation
outcomes must match contemporary theoretical expectations of motor deficit and
recovery because an assessment's theoretical underpinning forms the conceptual
basis for interpreting its score. The purpose of this study was to
investigate the theoretical framework of the Wolf Motor Function Test (WMFT) by
(1) determining whether all items measured a single underlying trait and (2)
examining the congruency between the hypothesized and the empirically determined
item difficulty orders. METHODS: Confirmatory factor analysis (CFA) and Rasch
analysis were applied to existing WMFT Functional Ability Rating Scale data from
189 participants in the EXCITE (Extremity Constraint-Induced Therapy Evaluation)
trial. Fit of a 1-factor CFA model (all items) was compared with the fit of a
2-factor CFA model (factors defined according to item object-grasp requirements)
with fit indices, model comparison test, and interfactor correlations. RESULTS:
One item was missing sufficient data and therefore removed from analysis. CFA fit
indices and the model-comparison test suggested that both models fit equally
well. The 2-factor model yielded a strong interfactor correlation, and 13 of 14
items fit the Rasch model. The Rasch item difficulty order was consistent with
the hypothesized item difficulty order. CONCLUSION: The results suggest that WMFT
items measure a single construct. Furthermore, the results depict an item
difficulty hierarchy that may advance the theoretical discussion of the person
ability versus task difficulty interaction during stroke recovery.

Langue : ANGLAIS