Reproducibility of Ventilatory Parameters, Dynamic Hyperinflation, and Performance in the Glittre-ADL Test in COPD Patients

Background: This study aimed to investigate the reproducibility of the ventilatory parameters and dynamic hyperinflation (DH) induced by the Glittre ADL-test (TGlittre) in chronic obstructive pulmonary disease (COPD) patients. Methods: Twenty-three patients with COPD underwent anthropometry, spirometry, TGlittre (TGlittre1 and TGlittre2) and pre- and post-test slow vital capacity. During the tests the ventilatory response was evaluated. Results: Regarding the TGlittre reproducibility, 87% of patients had a better performance in TGlittre2, and reduced on average 0.34 minute +/- 0.62 (p = 0.01) from TGlittre1 time to TGlittre2, showing a learning effect of 6.34%. The difference average between tests was correlated with the time spent in TGlittre1 (r = -0.52; p < 0.05). The TGlittre time was statistically reproducible (intraclass correlation coefficient = 0.97; p < 0.001). Final ventilation parameters and their variations presented low-to-high reproducibility, except respiratory rate. The DH was similar (p > 0.05) in both tests, with low reproducibility in percentage, while in liters it was not reproducible. Conclusions: The TGlittre time and ventilatory parameters are reproducible, while DH is variable in COPD patients. A 6-7% learning effect was shown, and it is recommended to perform two tests.