Correlates of physical activity in chronic obstructive pulmonary disease

Physical activity is a key dimension of functional status in people with chronic obstructive pulmonary disease (COPD), and the central target of interventions in this group.

To determine the relationships among functional performance measured as physical activity, functional capacity, symptom experiences, and health-related quality of life in people with COPD.

Cross-sectional, descriptive study. Convenience sample of 63 outpatients with COPD studied prior to entry into a pulmonary rehabilitation program.

Daily physical activity, as measured by an accelerometer, was strongly associated with maximal distance walked during a 6-minute walk test (r = .60, p < .00), level of airway obstruction (r = .37, p < .01), walking self-efficacy (r = .27, p < .05), and physical health status (r = .40, p < .01). Physical activity was not correlated with self-report of functional status. The only predictor of physical activity was the 6-minute walk test.

Accelerometer measurement of functional performance was most significantly related to walking abilities. This methodology represents a novel approach to measuring an important dimension of functional status not previously well quantified.