Test-retest reliability, concurrent validity, and sensitivity to change of mobility assessments in older adults with urinary incontinence

Urinary incontinence (UI) significantly impacts locomotor capacity in older adults. Reliable and valid assessment tools are crucial for monitoring treatment outcomes and guiding clinical decisions. This study aimed to investigate the test-retest reliability, concurrent validity, and sensitivity to change of the Timed Up and Go (TUG), Modified Four-Square Step Test (mFSST), 30-Second Chair Stand Test (30s-CST), and 2-Minute Walk Test (2MinWT) in older adults with UI. Seventy-seven incontinent older adults participated. To assess concurrent validity, the tests were compared with established reference measures: the Berg Balance Scale (BBS), Short Physical Performance Battery (SPPB), and Five Times Sit to Stand Test (FTST). The testing procedure followed a standardized timeline to prevent fatigue, with a one-hour interval between the two sessions for test-retest reliability. Excellent test-retest reliability was observed for all tests (ICC > 0.96). The tests demonstrated high time-efficiency, with mean completion times of 9.83s for TUG and 8.87s for mFSST. Strong correlations were found between the TUG, mFSST, 30s-CST, and 2MWT with the concurrent validity measures (BBS, SPPB, and FTST). Sensitivity to change was established with Minimal Detectable Change (MDC) values: TUG (0.81 s), mFSST (1.95 s), 30s-CST (1.63 times), and 2MinWT (7.32 m). The TUG, mFSST, 30s-CST, and 2MinWT demonstrate excellent psychometric properties in assessing locomotor capacity in this population. These simple, time-efficient tests can effectively monitor treatment response and detect clinically meaningful changes, with the TUG and 30s-CST being particularly recommended for rapid clinical screening in older adults with incontinence.