Application of the Modified Incremental Step Test for Pulmonary Rehabilitation

Abstract

Objective A modified incremental step test (MIST) performed in the home may facilitate entirely home-based pulmonary rehabilitation programs. The aims of this study were to investigate the reliability and responsiveness, and the utility of the MIST for exercise prescription in people with stable chronic lung disease. Methods The MIST was undertaken at the centre and home in random order, before and after pulmonary rehabilitation, with two tests at each time point. Reliability was assessed using intraclass correlation coefficient. Responsiveness was evaluated as effect size. The minimal important difference was appraised using distribution and anchor-based methods. In a sub-study, physiological responses to MIST were measured by a portable metabolic system, followed by a constant step rate test at 60% of peak oxygen uptake (v̇O2peak), to evaluate utility for exercise prescription. Results Forty-six participants were recruited (29% of eligible candidates). There was excellent reliability for number of steps recorded in home and centre-based settings (intraclass correlation coefficient 0.954, 95%CI 0.915 to 0.976). A small-moderate effect size was demonstrated following pulmonary rehabilitation (0.34) and the minimal detectable change was 7 steps. All participants in the sub-study achieved 60% of v̇O2peak and achieved steady state by the 4th minute, with 60% of v̇O2 peak corresponding to mean 37% (95%CI 29 to 44) of the MIST final level. Conclusions The MIST is reliable and responsive to pulmonary rehabilitation in people with stable chronic respiratory disease. It provides new opportunities to assess exercise capacity, prescribe exercise training and reassess exercise program outcomes in environments where established field walking tests are not feasible. Impact Pulmonary rehabilitation is a highly effective treatment that is underutilised worldwide. Home-based pulmonary rehabilitation may improve access for patients and deliver equivalent clinical outcomes, but is limited by the availability of a robust exercise test that can be used at home to assess exercise capacity and prescribe training intensity. This study tested the clinimetric properties of the modified incremental step test and demonstrated a new way to assess exercise capacity, prescribe exercise training of an appropriate intensity and reassess exercise capacity in environments where established field walking tests are not feasible.

Validity and reliability of a new incremental step test for people with chronic obstructive pulmonary disease

“…According to the systematic review mentioned before,11 a step test based on the characteristics of the ISWT is not yet available. In fact, only two step tests with an incremental and externally profile were identified, namely the Chester step test (CST)14 and the Modified Incremental Step Test (MIST) 15 16. MIST was developed as a modified version of the CST, as the CST was originally developed for healthy subjects,14 and has important disadvantages when applied in people with COPD, where their performances have a very short duration 17.…”

Telerehabilitation in pulmonary diseases

“…The modified incremental step test (MIST) is a reliable test of exercise capacity in people with chronic pulmonary disease, which is responsive to pulmonary rehabilitation [67]. The MIST can be used to prescribe endurance exercise training, and can be accurately and safely administered in the home with in-person supervision [67]. In people with chronic pulmonary disease, the utility of field exercise tests in remote settings for both accurate assessment of oxygen desaturation and exercise training prescription remains to be established.…”

“…Although history taking and evaluation using standardized questionnaires are considered appropriate for remote interactions by patients and clinicians [66], there are currently very few options of validated field exercise tests that both accurately assess desaturation and enable exercise prescription that can be administered at home or remotely for people referred to pulmonary rehabilitation [9 ▪ ]. The modified incremental step test (MIST) is a reliable test of exercise capacity in people with chronic pulmonary disease, which is responsive to pulmonary rehabilitation [67]. The MIST can be used to prescribe endurance exercise training, and can be accurately and safely administered in the home with in-person supervision [67].…”

Home-Pulmonary Rehabilitation Programme for Patients with Chronic Respiratory Diseases in Malaysia: A Mixed Method Feasibility Study

“…The modi ed incremental step test may be a viable option for the home environment. The modi ed incremental step test has been shown to be reliable and responsive in assessing exercise capacity in patients with CRDs who attend PR 25 . This may be implemented in the future Home-PR programme as it is an alternative assessment to assess exercise capacity at home and aid home exercise prescription for progression in home exercise prescription.…”