Step tests are feasible, safe, and can be used to evaluate exercise capacity at home after hospitalization for COVID-19

Abstract

Introduction: Step-based tests are commonly utilized to assess the exercise capacity of individuals with respiratory diseases. However, the feasibility and safety of the step tests have not yet been studied in individuals after COVID-19. Objective: To investigate the feasibility and safety of the six-minute step test (6MST) and the modified incremental step test (MIST) in assessing exercise capacity at home in individuals after hospitalization for COVID-19, and to identify factors associated with performance in these tests. Methods: Cross-sectional multicenter study with individuals hospitalized for COVID-19 fifteen days after hospital discharge. Participants performed spirometry, 6MST, and MIST during a single home visit. Adverse events were registered during and immediately after the tests. Results: Sixty-five participants were studied (50 ± 10 years old, 55% male). The feasibility was 96.9% and the incidence of adverse events was 13.8% in 6MST and 6.2% in MIST. The individuals performed 76.9% of the predicted on the 6MST, with 40% of the participants reaching 80% of the maximum HR and 31% presenting exercise-induced oxygen desaturation. In the MIST, the individuals performed 20% of the predicted, 23% of the participants reached 80% of the maximum heart rate, and 17% presented exercise-induced oxygen desaturation. Length of hospital stay and the use of mechanical ventilation were associated with test performance. Conclusion: 6MST and MIST are feasible, safe, and can be used to assess exercise capacity in a home environment in individuals after hospitalization for COVID-19. The performance in these tests was associated with a prolonged hospital stay and the use of mechanical ventilation.