Reliability and validity of instrumented timed up and go test in typical adults and elderly: a systematic review.

Objective: To summarize the available literature investigating the reliability and validity of the instrumented timed up and go (iTUG) in typical adults and elderly.

Data Sources: Data were collected from PubMed, Web of Science and hand searching up until July 15, 2024.

Study Selection: English-language studies investigating the reliability and validity for the 3-meter version of the iTUG in typical adults and elderly were included. Eligibility was blindly reviewed by two reviewers.

Data Extraction: Data on demographics, settings, reliability and validity of the iTUG were independently extracted by two reviewers. The methodological quality was blindly assessed by two reviewers using the COSMIN tools, and the certainty of evidence was evaluated by the modified GRADE approach.

Data Synthesis: 19 studies were included investigating 1729 participants, of which 334 typical adults and 1395 typical elderly. For intra-rater reliability (n = 1 study), ICC ranged from 0.39 (CI 95%, 0.30 to 0.50) to 0.97 (CI 95%, 0.95 to 0.98), and test-retest reliability (n = 2 studies) from 0.27 (CI 95%, -0.47 to 0.63) to 0.89 (CI 95%, 0.78 to 0.95), with inter-rater reliability (n = 1 study) generally sufficient, from 0.929 to 0.99 (CI not reported). One study on criterion validity showed sufficient agreement (ICC > 0.7) with the gold standard for most outcome measures, except for three outcome measures measuring time of turn. Moreover, 12 studies used iTUG to predict cognitive decline (AUC = 0.80), maximal mobility performance (R = 0.278), physical function (AUC up to 0.75), or falls (AUC up to 0.853 (CI 95%, 0.759 to 0.948)).

Conclusions: iTUG can be a reliable and valid tool for assessing mobility in adults and elderly. However, complexity and non-standardization of outcome measures reduces the reliability and validity of iTUG, which needs to be addressed in future research.