Reliability and Validity of Instrumented Timed Up and Go Test in Typical Adults and Elderly: A Systematic Review.

Abstract

To summarize the available literature investigating the reliability and validity of the instrumented Timed Up and Go (iTUG) in typical adults and elderly. Data were collected from PubMed, Web of Science, and hand searching up until July 15, 2024. English-language studies investigating the reliability and validity of the 3-meter version of the iTUG in typical adults and elderly were included. Eligibility was blindly reviewed by 2 reviewers. Data on demographics, settings, reliability, and validity of the iTUG were independently extracted by 2 reviewers. The methodological quality was blindly assessed by 2 reviewers using the Consensus-Based Standards for the Selection of Health Status Measurement Instruments tools, and the certainty of evidence was evaluated by the modified Grading of Recommendations Assessment, Developement and Evaluation (GRADE) approach. Nineteen studies were included investigating 1729 participants, of which 334 were typical adults and 1395 typical elderly. For intrarater reliability (n=1 study), intraclass correlation coefficient ranged from 0.39 (95% CI, 0.30-0.50) to 0.97 (95% CI, 0.95-0.98), test-retest reliability (n=2 studies) from 0.27 (95% CI, -0.47 to 0.63) to 0.89 (95% CI, 0.78-0.95), and interrater reliability (n=1 study) generally sufficient from 0.929 to 0.99 (CI not reported). One study on criterion validity showed sufficient agreement (intraclass correlation coefficient >0.7) with the criterion standard for most outcome measures, except for 3 outcome measures measuring time of turn. Moreover, 12 studies used iTUG to predict cognitive decline (area under the curve [AUC] = 0.80), maximal mobility performance (R²=0.278), physical function (AUC ≤0.75), or falls [(AUC ≤0.853 (95% CI, 0.759-0.948)]. iTUG can be a reliable and valid tool for assessing mobility in adults and elderly. However, the complexity and nonstandardization of outcome measures reduce the reliability and validity of iTUG, which needs to be addressed in future research.