Reproducibility of step tests in patients with bronchiectasis

Area of Science:

• Cardiopulmonary exercise testing
• Respiratory medicine
• Clinical exercise physiology

Background:

• Step tests are used to assess exercise capacity in chronic respiratory diseases.
• Their utility in bronchiectasis patients remains underexplored.

Purpose of the Study:

• To evaluate the reliability of the Chester step test (CST) and modified incremental step test (MIST) in bronchiectasis patients.
• To correlate step test outcomes with pulmonary function, heart rate (HR), and 6-minute walk test (6-MWT) distance.

Main Methods:

• Seventeen bronchiectasis patients underwent two trials each of CST, MIST, and 6-MWT on separate days.
• Measurements included number of steps (NOS), HR, SpO2, and perceived exertion (dyspnea and fatigue).

Main Results:

• Both CST and MIST demonstrated high reliability with similar NOS, HR, SpO2, and perceived exertion.
• CST was significantly shorter than MIST.
• NOS correlated with FEV1, 6-MWD, and peak HR for both tests.

Conclusions:

• CST and MIST are reliable and valid tools for assessing exercise capacity in bronchiectasis.
• MIST was better tolerated by patients compared to CST.
• Improved lung function and 6-MWT performance predict higher NOS and peak HR.