The Glittre-ADL test in non-hospitalized patients with post-COVID-19 syndrome and its relationship with muscle strength and lung function

BACKGROUND: Patients with post-acute COVID-19 syndrome tend to have limitations in performing activities of daily living, which may negatively impact performance during the Glittre-ADL test. This study aimed to verify if the Glittre-ADL test is associated with measures of pulmonary function, muscle function, and health-related quality of life in the assessment of non-hospitalized patients with sequelae of COVID-19, and also to identify the predictor variables related to the Glittre-ADL test in order to create a predictive model. METHODS: Cross-sectional study with 37 women with post-acute COVID-19 syndrome who underwent Glittre-ADL test. They performed pulmonary function tests and measurements of handgrip strength and quadriceps strength. Additionally, they completed the Post-COVID-19 Functional Status scale and the Short Form-36 questionnaire. FINDINGS: The mean value of Glittre-ADL test time was 4.8 ± 1.1 min, which was 163.7 ± 39.7% of the predicted. The Glittre-ADL test time showed correlation with diffusing capacity for carbon monoxide (r = -0.671, P < 0.0001), forced vital capacity (r = -0.588, P = 0.0001), maximum inspiratory pressure (r = -0.391, P = 0.015), handgrip strength (r = -0.453, P = 0.005), quadriceps strength (r = -0.591, P = 0.0001), and various dimensions of the Short Form-36 questionnaire. In the regression analysis, diffusing capacity for carbon monoxide, quadriceps strength, and forced vital capacity explained 64% of the Glittre-ADL test time variability. INTERPRETATION: In patients with post-acute COVID-19 syndrome, lung function and quadriceps strength strongly affect the time to perform Glittre-ADL test multiple tasks.