Reproducibility and Validity of the 6-Minute Walk Test Using the Gait Real-Time Analysis Interactive Lab in Patients with COPD and Healthy Elderly.
BACKGROUND
The 6-minute walk test (6MWT) in a regular hallway is commonly used to assess functional exercise capacity in patients with chronic obstructive pulmonary disease (COPD). However, treadmill walking might provide additional advantages over overground walking, especially if virtual reality and self-paced treadmill walking are combined. Therefore, this study aimed to assess the reproducibility and validity of the 6MWT using the Gait Real-time Analysis Interactive Lab (GRAIL) in patients with COPD and healthy elderly.


RESULTS
Sixty-one patients with COPD and 48 healthy elderly performed two 6MWTs on the GRAIL. Patients performed two overground 6MWTs and healthy elderly performed one overground test. Differences between consecutive 6MWTs and the test conditions (GRAIL vs. overground) were analysed. Patients walked further in the second overground test (24.8 m, 95% CI 15.2-34.4 m, p<0.001) and in the second GRAIL test (26.8 m, 95% CI 13.9-39.6 m). Healthy elderly improved their second GRAIL test (49.6 m, 95% CI 37.0-62.3 m). The GRAIL 6MWT was reproducible (intra-class coefficients = 0.65-0.80). The best GRAIL 6-minute walk distance (6MWD) in patients was shorter than the best overground 6MWD (-27.3 ± 49.1 m, p<0.001). Healthy elderly walked further on the GRAIL than in the overground condition (23.6 ± 41.4 m, p<0.001). Validity of the GRAIL 6MWT was assessed and intra-class coefficient values ranging from 0.74-0.77 were found.


CONCLUSIONS
The GRAIL is a promising system to assess the 6MWD in patients with COPD and healthy elderly. The GRAIL 6MWD seems to be more comparable to the 6MWDs assessed overground than previous studies on treadmills have reported. Furthermore, good construct validity and reproducibility were established in assessing the 6MWD using the GRAIL in patients with COPD and healthy elderly.
Department of Research and Education, CIRO, Horn, the Netherlands.|NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Department of Human Movement Science, Maastricht, the Netherlands.
Wai-Yan
http://orcid.org/0000-0003-1379-958X
WY
Liu
NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Department of Human Movement Science, Maastricht, the Netherlands.
Kenneth
K
Meijer
Department of Research and Education, CIRO, Horn, the Netherlands.
Jeannet M
JM
Delbressine
NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Department of Human Movement Science, Maastricht, the Netherlands.
Paul J
PJ
Willems
Department of Research and Education, CIRO, Horn, the Netherlands.|Department of Respiratory Medicine, Maastricht University Medical Centre+, Maastricht, the Netherlands.
Frits M E
FM
Franssen
Department of Research and Education, CIRO, Horn, the Netherlands.|Department of Respiratory Medicine, Maastricht University Medical Centre+, Maastricht, the Netherlands.
Emiel F M
EF
Wouters
Department of Research and Education, CIRO, Horn, the Netherlands.
Martijn A
MA
Spruit
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003199:Computer Systems; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D015203:Reproducibility of Results; D000070857:Walk Test