Daily walking intensity as a predictor of quality of life in patients with chronic obstructive pulmonary disease

PURPOSE: This study aimed to assess independent predictors of quality of life (QOL) in patients with chronic obstructive pulmonary disease, in particular, to evaluate the relationship between QOL and functional exercise capacity measured with an activity monitor. METHODS: Functional exercise capacity was measured with an accelerometer-based walking intensity. QOL was assessed by Short Form-36 and Saint Georges Respiratory Questionnaire. Stepwise multivariate regression analyses were used to identify significant independent predictors of health-related QOL. RESULTS: Daily walking intensity (fast walk) was the only significant independent predictor of the Short Form-36 domains 'physical function' (P = 0.002) and 'role physical' (P = 0.034). Age and depression were significant independent predictors of the domain 'social functioning' (P = 0.035 and P = 0.002, respectively). Age and fast walk were significant independent predictors of the domain 'mental health' (P = 0.006 and P = 0.017, respectively). Percent predicted forced expiratory volume in 1 s and fast walk were both significant independent predictors of the domains 'general health' (P = 0.04 and P = 0.02, respectively) and 'physical component score' (P = 0.038 and P = 0.017, respectively). In terms of the Saint Georges Respiratory Questionnaire, fast walk was a significant independent predictor of 'activity score' (P = 0.001), 'impact score' (P = 0.022), and 'total score' (P = 0.01). CONCLUSIONS: QOL is an important aspect to be integrated into long-term disease management and the assessment of daily walking intensity using accelerometry can provide additional information about the patient's functional status and well-being during a certain period