Article

The minimal detectable change (MDC) is the smallest amount of
difference in individual scores that represents true change (beyond random
measurement error). The MDCs of the Timed "Up & Go" Test (TUG) and the Dynamic
Gait Index (DGI) in people with Parkinson disease (PD) are largely unknown,
limiting the interpretability of the change scores of both measures.
The purpose of this study was to estimate the MDCs of the TUG and the DGI in
people with PD. DESIGN: This investigation was a prospective cohort study.
METHODS: Seventy-two participants were recruited from special clinics for
movement disorders at a university hospital. Their mean age was 67.5 years, and
61% were men. All participants completed the TUG and the DGI assessments twice,
about 14 days apart. The MDC was calculated from the standard error of
measurement. The percentage MDC (MDC%) was calculated as the MDC divided by the
mean of all scores for the sample. Furthermore, the intraclass correlation
coefficient was used to examine the reproducibility between testing sessions
(test-retest reliability). RESULTS: The respective MDC and MDC% of the TUG were
3.5 seconds and 29.8, and those of the DGI were 2.9 points and 13.3. The
test-retest reliability values for the TUG and the DGI were high; the intraclass
correlation coefficients were .80 and .84, respectively. LIMITATIONS: The study
sample was a convenience sample, and the participants had mild to moderately
severe PD. CONCLUSIONS: The results showed that the TUG and the DGI have
generally acceptable random measurement error and test-retest reliability. These
findings should help clinicians and researchers determine whether a change in an
individual patient with PD is a true change.

Langue : ANGLAIS