Reliability, Agreement and Minimal Detectable Change of the Timed Up & Go and the 10-Meter Walk Tests in Older Patients with COPD

Abstract

This study aimed to determine the interrater and intrarater reliability and agreement and the minimal detectable change (MDC) of the Timed Up & Go (TUG) test and the 10-Meter Walk Test (10MWT) in older patients with Chronic Obstructive Pulmonary Disease (COPD). Patients (≥ 60 years old) living in the community were asked to attend 2 sessions with 48-72-hour interval. In session 1, participants completed the TUG and 10MWT twice (2 trials) and were assessed by 2 raters. In session 2, they repeated the tests twice and were assessed by 1 rater. Interrater and intrarater reliability were calculated for the exact scores (using data from trial 1) and mean scores (mean of 2 trials) using Intraclass Correlation Coefficients (ICC2,1 and ICC2,2, respectively). Interrater and intrarater agreement were explored with the Bland & Altman method. The MDC95 was calculated from the standard error of measurement. Sixty participants (72.43 ± 6.90 years old) completed session 1 and 41 participants session 2. Excellent ICC values were found for the TUG test (interrater: ICC2,1 = 0.997 ICC2,2 = 0.999; intrarater: ICC2,1 = 0.921 ICC2,2 = 0.964) and 10MWT (interrater: ICC2,1 = 0.992 ICC2,2 = 0.997; intrarater: ICC2,1 = 0.903 ICC2,2 = 0.946). Good interrater and intrarater agreement was also found for both tests. The MDC95 was 2.68 s and 1.84 s for the TUG and 0.40 m/s and 0.30 m/s for the 10MWT considering the exact and mean scores, respectively. Findings suggest that the TUG test and the 10MWT are reliable and have acceptable measurement error. Therefore, these measures may be used to assess functional balance (TUG) and gait (10MWT) deficits in older patients with COPD.