Self-reported daily walking time in COPD: relationship with relevant clinical and functional characteristics.

Quantifying physical activity in chronic obstructive pulmonary disease (COPD) is important as physical inactivity is related to poor health outcomes. This study analyzed the relationship between patients' self-reported daily walking time and relevant characteristics related to COPD severity. Pooled analysis was performed on data from four observational studies on which daily walking time was gathered from a personal interview. Patients were classified as physically inactive if walking time was The mean daily walking time of 5,969 patients was 66 (standard deviation [SD] 47) min/day; 893 (15%) patients were inactive. A linear dose-response relationship was observed between walking time and the modified Medical Research Council (mMRC) dyspnea score, admissions, COPD assessment test (CAT), body mass index, airway obstruction, dyspnea, exacerbation (BODEx) index, and Charlson index (P3, post-bronchodilator forced expiratory volume in the first second 4, and CAT score >30. Lower self-reported walking times are related to worse markers of disease severity in COPD