Understanding the measurement properties of the incremental shuttle walk test in patients with severe asthma.

Background And Objective: We investigated the repeatability and validity of the incremental shuttle walk test (ISWT) distance compared to peak oxygen uptake (VO ) during maximal incremental cycle ergometer (ICE) and treadmill (ITM) tests in adults with severe asthma.

Methods: Adults with severe asthma, Medical Research Council (MRC) dyspnoea ≥2, were recruited from specialists caring for patients with severe asthma. All participants performed three ISWT (familiarization and two subsequent tests on the same day), an ICE and an ITM in a randomized order, on separate days, to intolerance with expiratory gas analysis.