TY - JOUR T1 - Reproducibility and Validity of the 6-Minute Stationary Walk Test Associated With Virtual Reality in Subjects With COPD JF - Respiratory Care DO - 10.4187/respcare.06237 SP - respcare.06237 AU - Maria MC Frade AU - Ivanize MM dos Reis AU - Renata P Basso-Vanelli AU - Alexandre F Brandão AU - Mauricio Jamami Y1 - 2019/01/29 UR - http://rc.rcjournal.com/content/early/2019/01/29/respcare.06237.abstract N2 - BACKGROUND: The importance of evaluating the functional capacity of patients with COPD is well known, and there is a wide range of tests described in the literature. The 6-min stationary walk test associated with virtual reality (STVR-6) was created in light of the current limitations of evaluation tests. It does not require a large physical space or sophisticated equipment, and it is not costly; furthermore, it can be performed by a single rater. The objective of this study was to evaluate intra- and inter-rater reproducibility and to verify the criterion validity of the STVR-6.METHODS: 50 subjects with COPD were evaluated over the course of 3 d. The execution order of the tests was randomized; the STVR-6 was performed over 2 d, and the 6-min walk test was performed in 1 d. The 6-min walk distance variables and number of steps in the STVR-6 were obtained with a gas analysis performed for both tests.RESULTS: Relative reproducibility was found for intraclass correlation coefficient values (0.57–0.94, P < .001) between the number of steps and the highest value of oxygen consumption during the test (V̇O2 peak), intra- and inter-rater. In terms of absolute reproducibility, the standard error of measurement and minimum detectable difference values were verified. In the Bland-Altman analysis, the intra- and inter-rater mean difference values were 21 and 17 steps and 0.002 and 0.242 mL/min/kg, respectively. Pearson correlation values were 0.57–0.75 (P < .001) between the number of steps and V̇O2 peak.CONCLUSIONS: STVR-6 had excellent intra-rater reproducibility and excellent to good inter-rater reproducibility, but the high values of error measures demonstrated that there is a learning effect and a need to perform at least 2 tests. In addition, there was high to moderate correlation between the STVR-6 and the 6-min walk test. Therefore, the STVR-6 proved to be reproducible and valid for evaluating the functional capacity of subjects with COPD. ER -