Reliability, Sensitivity and Validity of the 6 Minute Step Test in Chronic Obstructive Pulmonary Disease (COPD) Patients

Chronic Obstructive Pulmonary Disease (COPD) leads to a reduction in exercise capacity that affects the quality of life and increases mortality of these patients. So, exercise tests are considered as an essential component of the clinical evaluation of the patients with COPD. The objective of this study is to evaluate the reproducibility sensitivity and validity of the Six Minute Step Test (6MST) in patients with COPD and in health volunteers, and verify its relation with the "Body-Mass Index, Airways Obstruction, Dyspnea and Exercise Capacity" Index (BODE). This Observational, Transversal, Prospective study will be conducted in the "Special Unit of Respiratory Physiotherapy", of the "Federal University of São Carlos". To participate in this study, 120 subjects, both gender, will be invited and will be allocated in five groups: Group I (30 healthy young subjects of 17 to 27 years old), Group II (30 healthy elderly individuals of 60 to 75 years old), and patients COPD, 60 to 80 years old, with mild, moderate, severe and very severe obstruction determined by the forced expiratory volume in one second (FEV1) by forced vital capacity (FVC) relation "FEV1/FVC" \<70% and FEV1 in predict percentage \< 80% composing the Group III (20 COPD patients in GOLD stage I), Group IV (20 COPD patients in GOLD stage II) and Group V (20 patients COPD stages III and IV). All subjects will be submitted to body composition and anthropometric assessment, pulmonary function test, three 6-minutes walk test (6MWT) and three 6MST. Furthermore, the patients of the groups III, IV and V will answer the Modified Medical Research Council (mMRC) scale, and BODE index will be calculated to each of them.