@Article{info:doi/10.2196/67322,
author="B{\"o}ttinger, Melissa Johanna
and Mellone, Sabato
and Klenk, Jochen
and Jansen, Carl-Philipp
and Stefanakis, Marios
and Litz, Elena
and Bredenbrock, Anastasia
and Fischer, Jan-Philipp
and Bauer, J{\"u}rgen M
and Becker, Clemens
and Gordt-Oesterwind, Katharina",
title="A Smartphone-Based Timed Up and Go Test Self-Assessment for Older Adults: Validity and Reliability Study",
journal="JMIR Aging",
year="2025",
month="Mar",
day="21",
volume="8",
pages="e67322",
keywords="timed up and go test; self-assessment; instrumented assessment; technology-based assess-ment; physical capacity; mobility; aged; mobile applications; smartphone; diagnostic self evaluation",
abstract="Background: The Timed Up and Go test (TUG) is recommended as an evidence-based tool for measuring physical capacity. Instrumented TUG (iTUG) approaches expand classical supervised clinical applications offering the potential of self-assessment for older adults. Objective: This study aimed to evaluate the concurrent validity and test-retest reliability of a smartphone-based TUG self-assessment ``up{\&}go app.'' Methods: A total of 52 community-dwelling older adults (>67 years old) were recruited. A validated and medically certified system attached with a belt at the lower back was used as a reference system to validate the ``up{\&}go app'' algorithm. The participants repeated the TUG 5 times wearing, a smartphone with the ``up{\&}go app'' in their front trouser pocket and an inertial sensor to test the concurrent validity. A subsample of 37 participants repeated the ``up{\&}go app'' measurement 2 weeks later to examine the test-retest reliability. Results: The correlation between the ``up{\&}go app'' and the reference measurement was r=0.99 for the total test duration and r=0.97 for the 5 single repetitions. Agreement between the 5 repetitions was intraclass correlation coefficient (ICC)=0.9 (0.84‐0.94). Leaving out the first repetition, the agreement was ICC=0.95 (0.92‐0.97). Test-retest agreement had an ICC=0.79 (0.53‐0.9). Conclusions: The duration of 5 repetitions of the TUG test, measured with the pocket-worn ``up{\&}go app,'' was very consistent with the results of a lower-back sensor system, indicating excellent concurrent validity. Participants walked slower in the first round than in the other 4 repetitions within a test run. Test-retest reliability was also excellent. The ``up{\&}go app'' provides a useful smartphone-based approach to measure 5 repetitions of the TUG. The app could be used by older adults as a self-screening and monitoring tool of physical capacity at home and thereby help to early identify functional limitations and take interventions when necessary. ",
issn="2561-7605",
doi="10.2196/67322",
url="https://aging.jmir.org/2025/1/e67322",
url="https://doi.org/10.2196/67322"
}