Performance difference on the six-minute walk test on tracks of 20 and 30 meters for patients with chronic obstructive pulmonary disease: validity and reliability

Abstract

Background: Functional capacity assessment is important in patients with chronic obstructive pulmonary disease (COPD). It can be performed by the six-minute walk test (6MWT) on a 30meter track. However, such space is not always available in clinical settings. Objectives: To compare the performance between the 6MWT on a 30-(6MWT 30 ) and 20-meter (6MWT 20 ) track; to evaluate the validity and reliability of the 6MWT 30 and the 6MWT 20 ; and to determine for which patients track length has the greatest impact on performance. Methods: Patients with COPD randomly performed two 6MWT 30 and two 6MWT 20 on two different days and were also assessed using the COPD Assessment Test (CAT) and modified Medical Research Council (mMRC) scale. Results: Thirty patients (23 men; mean ± standard deviation FEV 1 %pred: 45.6 ± 12.1) participated in the study. They walked a greater distance on the 6MWT 30 than on the 6MWT 20 [mean difference: 22.1 m (95% CI: 12, 32 m)]. The longer the 6MWT 30 distance, the greater the difference between the 2 tests (r = 0.51; p = 0.004). The 6MWT 20 showed high reliability [ICC: 0.96 (95% CI: 0.77, 0.99)] and the results were associated with the distance walked on the 6MWT 30 (r = 0.86), CAT (r = −0.53), and mMRC (r = −0.62). Patients who walked ≥430 m in the 6MWT 30 presented a difference between the tests greater than those who walked <430 m (34.5 ± 23.3 m vs. 12.6 ± 24.1 m; respectively; p = 0.01).

Effects of Course Length on the Six-Minute Walk Test in Healthy Adults: A Pilot Study

“…Overall, healthy adults did not walk further on a 30m course when compared to either a 15m course (p = .06) or a 20m course (p = .08). Our results are in contrast with previously reported scholars who found course length to affect distance walked [1,[9][10][11] . Although our study is inconsistent with previously reported literature, our study is one of the few that used healthy adults.…”

“…In our pilot study, course length did not affect distance walked in healthy adults aged 18-30. These results are inconsistent with previous studies which outlined course length affected distance ambulated [1,[9][10][11]. One explanation for this inconsistency is our sample size of age 18-30, healthy adults.…”

“…Ng, et al [9] found a 14m difference when comparing a 30m course to a 20m course, 41m difference when comparing a 30m course to a 10m course, and a 21m difference when comparing a 20m course to a 10m course. Similarly, Klein, et al [10] reported a 22.1m difference when comparing a 30m course with a 20m course. Klein, et al [10] also found performance to be a moderate indicator of distance walked.…”

“…Similarly, Klein, et al [10] reported a 22.1m difference when comparing a 30m course with a 20m course. Klein, et al [10] also found performance to be a moderate indicator of distance walked. Gochicoa-Rangel, et al [11] reported a mean difference of 25m in their healthy control group and 17m in their chronic lung disease group when comparing a 15m and 30m course.…”

Comparison between 20 and 30 meters in walkway length affecting the 6-minute walk test in patients with chronic obstructive pulmonary disease: A randomized crossover study

“…Our study found significant difference of 6MWD between a 20-m and a 30-m walkway in that walking distance on 20-m walkway is shorter than on a 30-m by an average of 22.03 m and had 4.88 more turns. These results correspond to the study of Klein SR, et al [10]. They found that, in COPD patients, 6MWD with 30-m walkway was significantly longer than 20-m walkway (mean difference in 22.1 m) [10].…”