Reliability of measurements obtained with the Timed "Up & Go" Test in people with Parkinson disease

Background and Purpose. The Timed "Up & Go" Test (TUC) is used to measure t he ability of patients to perform sequential locomotor tasks that incorpora te walking and turning. This study investigated the retest reliability, int errater reliability, and sensitivity of TUG scores in detecting changes in mobility in subjects with idiopathic Parkinson disease (PD). Subjects. The performance of 12 people with PD was compared with that of 12 age-matched c omparison subjects without PD. Methods. The subjects with PD completed 5 tr ials of the TUG after withdrawal of levodopa for 12 hours ("off " phase of the medication cycle) as well as an additional 5 trials 1 hour after levodo pa was administered ("on" phase of the medication cycle). They were scored on the Modified Webster Scale at both sessions. The comparison subjects als o performed 5 TUG trials. All trials were videotaped and timed by 2 experie nced raters. The videotape was later rated by 3 experienced clinicians and 3 inexperienced clinicians. Results. For the subjects with PD, within-sessi on performance was highly consistent, with correlations (r) ranging from .8 0 to .98 for the "off " phase and from .73 to .99 for the "on" phase. The p erformance of the comparison subjects across the 5 trials was also highly c onsistent (r = .90-.97). Comparisons showed differences between trials 1 an d 2 on the TUG for both groups. Removal of data for trial 1 (the practice t rial) further enhanced retest reliability. There was close agreement in TUG scores among raters despite different levels of experience (intraclass cor relation coefficient [3,1] = .87-.99). Mean TUG scores were different betwe en the "on" and "off " phases of the levodopa cycle and between subjects wi th PD and comparison subjects during the "on" phase. Conclusion and Discuss ion. Retest reliability and interrater reliability of the TUG measurements were high, and the measurements reflected changes in performance according to levodopa use. The TUG can also be used to detect differences in performa nce between people with PD and elderly people without PD.