Intra-session reliability of the Imagined Timed Up and Go Test: intra- and simultaneous inter-rater analyses in community-dwelling older adults

The reliability of the Imagined Timed Up and Go Test (ITUG) for community-dwelling older adults remains unclear, warranting quantitative assessment before broad clinical use.</p> <p>We aimed to evaluate the ITUG’s intra-session intra-rater and inter-rater reliability.</p> <p>Timed Up and Go Test (TUG) and ITUG were performed in older adults with normal cognitive function.

EE was defined as ITUG−TUG and Delta time (%) as (TUG−ITUG)/TUG × 100; negative EE and positive Delta time both indicate overestimation of physical ability. Intra-rater reliability was evaluated using repeated within-session measurements and inter-rater reliability using simultaneous timing of the same performance by two examiners within one same-day session. Intra-rater and inter-rater reliability were evaluated by calculating intraclass correlation coefficients (ICCs) using a two-way mixed-effects, absolute-agreement, single-measures model for intra-rater reliability (ICC_A,1) and two-way random-effects, absolute-agreement model for inter-rater reliability, reported as average-measures (ICC_2,2) and single-measures (ICC_2,1).