Six-minute stepper test in hospitalized elderly patients: Convergent validity, test-retest reliability and safety

OBJECTIVE: To evaluate the convergent validity of the six-minute stepper test (6MST) with the variables used in the diagnosis of sarcopenia (appendicular muscle mass, handgrip strength and six-meter gait speed test), as well as to evaluate test-retest reliability and safety when applied to hospitalized elderly patients. Finally, we aimed to compare the performance in the 6MST between hospitalized elderly patients and healthy elderly from the community. MATERIALS AND METHODS: Observational and cross-sectional study. Elderly patients admitted to a private hospital and healthy elderly from the community were recruited. On the first day, the patients included underwent the following assessments: anthropometric, handgrip strength (HGS), six-meter gait speed test (6GST) and 6MST. On the second day, before breakfast, patients underwent body composition assessment. The healthy elderly were evaluated on a single day and performed only anthropometric assessment and 6MST. RESULTS: 30 hospitalized patients (age 71.0±7.9 years) and 15 healthy elderly (age 68.1±5.8 years) were included. There was a high correlation of 6MST with 6GST (r = 0.78; p<0.001), moderate correlation with HGS (r = 0.59; p<0.001) and low correlation with appendicular muscle mass (r = 0.45; p = 0.01). There was no statistical difference between the first and second 6MST performed by hospitalized elderly (196.2±91.0 cycles vs. 191.3±103.7 cycles; p = 0.66), in addition to an excellent agreement between these measures (ICC = 0.90; 95% IC 0.78–0.95). Only one adverse event (3.3%) occurred in the sample. CONCLUSION: 6MST showed convergent validity with the functional variables used in the diagnosis of sarcopenia. In addition, excellent test-retest reliability was observed, which indicates the need for a single assessment in hospitalized elderly patients. The prevalence of adverse events during the application of the test is low, without resulting in clinical symptoms; therefore, the test is considered safe for this population. In addition, hospitalized elderly patients perform worse in the 6MST compared to healthy elderly from the community.