Six-minute walk test in pulmonary rehabilitation: do all patients need a practice test?

BACKGROUND AND OBJECTIVE: The six-minute walk test (6MWT) is widely used as an outcome measure in pulmonary rehabilitation programs (PRP). A learning effect for the test has been reported in COPD; however, limited data exist in patients with other respiratory diagnoses. The objectives of this study were to: (i) report the magnitude of change in 6MWD with test repetition in patients referred to an outpatient PRP, and (ii) compare the magnitude of change in 6MWD with test repetition in patients with COPD, interstitial lung disease (ILD), bronchiectasis and asthma.

METHODS: Retrospective study of 349 patients with stable COPD (n = 245), ILD (n = 21), bronchiectasis (n = 33) or asthma (n = 50) who performed two 6MWT at enrollment into a PRP.

RESULTS: 6MWD increased in all groups on the second test (all P < 0.001). At least 80% of patients in each diagnostic group walked further on their second 6MWT. The magnitude of change (mean, 95% CI) was greater (P < 0.05) in the COPD (37 m, 95% CI: 33-41 m) and ILD (41 m, 95% CI: 27-55 m) cohorts compared with the bronchiectasis (22 m, 95% CI: 14-31 m) and asthma (19 m, 95% CI: 11-27 m) cohorts.

CONCLUSIONS: Respiratory diagnosis influences the magnitude of the learning effect for the 6MWT. The findings support the recommendation of a practice 6MWT at baseline assessment in order to provide an accurate measure of the effects of rehabilitation on 6MWD.