Dual tasking with the timed “Up & Go” test improves detection of risk of falls in people with Parkinson disease

Background. Falls are a common and disabling feature of Parkinson disease (PD). Early identification of patients at greatest risk of falling is a key goal of physical therapy assessment. The Timed “Up & Go” Test (TUG), a frequently used mobility assessment tool, has moderate sensitivity and specificity for identifying fall risk.

Objective. The study objective was to investigate whether adding a task (cognitive or manual) to the TUG (TUG-cognitive or TUG-manual, respectively) increases the utility of the test for identifying fall risk in people with PD.

Design. This was a retrospective cohort study of people with PD (N=36).

Methods. Participants were compared on the basis of self-reported fall exposure in the preceding 6 months (those who had experienced falls [“fallers”] versus those who had not [“nonfallers”]). The time taken to complete the TUG, TUG-cognitive, and TUG-manual was measured for both groups. Between-group differences were calculated with the Mann-Whitney U test. The discriminative performance of the test at various cutoff values was examined, and estimates of sensitivity and specificity were based on receiver operating characteristic curve plots.

Results. Fallers took significantly longer than nonfallers (n=19) to complete the TUG under all 3 conditions. The TUG-cognitive showed optimal discriminative performance (receiver operating characteristic area under the curve=0.82; 95% confidence interval [CI] =0.64, 0.92) at a cutoff of 14.7 seconds. The TUG-cognitive was more likely to correctly classify participants with a low risk of falling (positive likelihood ratio = 2.9) (<14.7 seconds) and had higher estimates of sensitivity (0.76; 95% CI=0.52, 0.90) than of specificity (0.73; 95% CI=0.51, 0.88) at this threshold (negative likelihood ratio=0.32).

Limitations. Retrospective classification of fallers and nonfallers was used.

Conclusions. The addition of a cognitive task to the TUG enhanced the identification of fall risk in people with PD. The TUG-cognitive should be considered a component of a multifaceted fall risk assessment in people with PD.