Six-minute walk test in patients with chronic obstructive pulmonary disease: Comparison with and without active coaching

Aim. To assess the sk-minute walk test (6 MWT) with and without encouragement in patients with severe chronic obstructive pulmonary disease (COPD). Methods. Thirty-eight COPD patients (72 ± 6 years, FEV 37 ± 12% pred.) performed 6 MWT in random order in two non consecutive days. The first test was carried out including encouragement according to the ATS standard procedure (WTE), the second without any phrase of encouragement (WTNE). Subgroup analysis has been also performed by dividing patients on the basis of their own level of exercise tolerance at the baseline test (6 MWT < 300 and > 300 meters). The measured variables included the total distance covered (M), subjective dyspnoea (D) and leg fatigue (F) as assessed by Borg scale, the main cardio-respiratory parameters as recorded along the test. Results. M was significantly higher during WTE than during WTNE (370 ± 78 and 336 ± 79 meters, respectively), whereas D and F only showed a non significant trend to increase during WTE. No significant differences of the other physiological parameters have been recorded between the two tests. Results similar to those obtained in the whole group have also been observed in both pre-defined subgroups of patients. Conclusions. Our study has shown that the encouraged recommended modality of 6 MWT is associated to a better result in terms of walked distance as compared with the non encouraged test in severe COPD patients. This was not associated with a detrimental effect on the cardiopulmonary responses.