Reliability of the Brazilian Portuguese version of the fatigue severity scale and its correlation with pulmonary function, dyspnea, and functional capacity in patients with COPD.

Objective: To describe the intra-rater and inter-rater reliability of the Brazilian Portuguese version of the fatigue severity scale (FSS) in patients with COPD and to identify the presence of its association with parameters of pulmonary function, dyspnea, and functional capacity.

Methods: This was an observational cross-sectional study involving 50 patients with COPD, who completed the FSS in interviews with two researchers in two visits. The FSS scores were correlated with those of the Medical Research Council (MRC) scale, as well as with FEV1, FVC, and six-minute walk distance (6MWD).