Reliability and validity of the Glittre-ADL test to assess the functional status of patients with interstitial lung disease

Abstract

The study objective was to investigated the reliability and validity of the ADL-Glittre test (TGlittre) to assess the functional status of patients with interstitial lung disease (ILD). Twenty-one individuals with ILD participated (age: 63 ± 11 years; DLCO: 51.0 ± 12.6%predicted), evaluated with body plethysmography, Saint George Respiratory Questionnaire, modified Medical Research Council dyspnea scale, six-minute walk test (6MWT) and monitoring of physical activity of daily living. Two TGlittre were performed, with an interval of 30 minutes between them. The TGlittre demonstrated high test-retest reliability, with an intraclass correlation coefficient of 0.90 (95%CI: 0.75-0.96; p < 0.001). Nineteen patients (90.5%) performed better on the second test (mean difference between TGlittre 1 and 2: -0.57 ± 0.96 minute; p = 0.001), with a learning effect of 11.6%. The time in TGlittre correlated with 6MWT (r = -0.70; p = 0.002) and with the total energy expenditure in physical activity of daily living (r = -0.52; p = 0.02). In %predicted, TGlittre and 6MWT also correlated (r = -0.50; p = 0.04). Correlations were observed between TGlittre and pulmonary function variables (r = -0.47 to -0.57; p = 0.01 to p = 0.04). There was no difference in the physiological response between TGlittre 1 and 2, and between TGlittre and 6MWT (p > 0.05). In conclusion, the TGlittre is reliable and valid for assessing functional status of patients with ILD.