Article

OBJECTIVE: To assess changes and responsiveness in outcome measures of mobility,
balance, muscle strength and manual dexterity in adults with myotonic dystrophy
type 1. DESIGN: A 9-year longitudinal study conducted with 113 patients. METHODS:
The responsiveness of the Timed Up and Go test, Berg Balance Scale, quantitative
muscle testing, grip and pinch-grip strength, and Purdue Pegboard Test was
assessed using criterion and construct approaches. Patient-reported perceived
changes (worse/stable) in balance, walking, lower-limb weakness, stair-climbing
and hand weakness were used as criteria. Predefined hypotheses about expected
area under the receiver operating characteristic curves (criterion approach) and
correlations between relative changes (construct approach) were explored.
RESULTS: The direction and magnitude of median changes in outcome measures
corresponded with patient-reported changes. Median changes in the Timed Up and Go
test, grip strength, pinch-grip strength and Purdue Pegboard Test did not, in
general, exceed known measurement errors. Most criterion (72%) and construct
(70%) approach hypotheses were supported. Promising responsiveness was found for
outcome measures of mobility, balance and muscle strength. Grip strength and
manual dexterity measures showed poorer responsiveness. CONCLUSION: The
performance-based outcome measures captured changes over the 9-year period and
responsiveness was promising. Knowledge of measurement errors is needed to
interpret the meaning of these longitudinal changes.

Langue : ANGLAIS