Reliability and concurrent validity of the Expanded Timed Up-and-Go test in older people with impaired mobility.

BACKGROUND AND PURPOSE: 'Expanded Timed Up-and-Go' (ETUG) was developed to assess each of the subtasks of the 'Timed Up-and-Go' (TUG). The aim of the study was to test the intrarater, interrater, test-retest reliability and internal consistency of the ETUG, and the concurrent validity with the TUG.

METHODS: The present study is a reliability and a validity study. Twenty-eight subjects (80 +/- 4.1 years) with balance and gait problems were included. Three raters timed the ETUG subtasks from a video, using a computer-based scoring programme, and the total ETUG time was calculated. TUG was registered by a regular stopwatch.

RESULTS: The intrarater and interrater reliability (intraclass correlation [ICC][1,1]) ranged from 0.55 to 0.97. The test-retest reliability (ICC[1,1]) ranged from 0.54 to 0.85. The absolute measurement error of the total time (1.96 S(w)) was 2.8 seconds. The internal consistency (Cronbach's alpha) was 0.74. The correlation (Pearson's r) between ETUG total time and TUG after correcting for attenuation caused by restricted reliability in each of the measures was 0.85.

CONCLUSION: The ETUG scored from a video shows a good reliability for experienced raters and acceptable internal consistency. The ETUG showed a higher reliability than TUG when tested on the same sample of older subjects with impaired mobility, and the high concurrent validity between ETUG and TUG suggests that the two tests may have similar properties. Since ETUG also adds new information compared with TUG, we suggest that ETUG is an interesting alternative to existing clinical tests of mobility.