Reliability, Validity and Minimal Detectable Change in the Timed Up and Go and Five Times Sit to Stand Tests in Older Adults with Early Cognitive Loss

Background: Five times sit to stand test (FTSTS) and Timed Up and Go (TUG) have been used in clinical settings as a measure of physical performance in older adults with and without cognitive dysfunction. The validity and reliability of these measures have been established in older adults with differing diagnoses, but not in those with early cognitive loss. The purpose of this study was to evaluate the validity, reliability and minimal detectable change of FTSTS and TUG in older adults with early cognitive loss. Methods: Performance on the FTSTS and TUG was assessed in 26 older adults. Test-retest reliability was examined using ICC2,1 and absolute (SEM) reliability as well as the MDC95. Pearson’s correlation coefficient was used to examine relationships between the measures and gait speed, to determine construct validity. Bland- Altman plots were constructed to assess systematic bias. Results: FTSTS had high test-retest reliability (ICC2,1=0.89), small SEM (1.20 s), and the MDC95 was 3.54 s. TUG had high test-retest reliability (ICC2,1=0.81), small SEM (1.60 s), and the MDC95 was 5.37 s Correlation coefficients between the measures and gait speed indicates that FTSTS and TUG are valid measures of dynamic balance in older adults with early cognitive loss. Conclusions: To be considered real change beyond measurement error, change in FTSTS performance