Abstract
RATIONALE: Increasing physical activity is a key therapeutic aim in chronic obstructive pulmonary disease (COPD). Pulmonary rehabilitation (PR) improves exercise capacity, but there is conflicting evidence regarding its ability to improve physical activity levels. OBJECTIVES: To determine whether using pedometers as an adjunct to PR can enhance time spent in at least moderate-intensity physical activity (time expending ≥3 metabolic equivalents [METs]) by people with COPD. METHODS: In this single-blind randomized controlled trial, participants were assigned 1:1 to receive a control intervention (PR comprising 8 wk, two supervised sessions per week) or the trial intervention (PR plus pedometer-directed step targets, reviewed weekly for 8 wk). In the randomization process, we used minimization to balance groups for age, sex, FEV(1) percent predicted, and baseline exercise capacity and physical activity levels. Outcome assessors and PR therapists were blinded to group allocation. The primary analysis was based on the intention-to-treat principle. MEASUREMENTS AND MAIN RESULTS: The primary outcome was change from baseline to 8 weeks in accelerometer-measured daily time expending at least 3 METs. A total of 152 participants (72% male; mean [SD] FEV(1) percent predicted, 50.5% [21.2]; median [first quartile, third quartile] time expending ≥3 METs, 46 [21, 92] min) were enrolled and assigned to the intervention (n = 76) or control (n = 76) arm. There was no significant difference in change in time expending at least 3 METs between the intervention and control groups at 8 weeks (median [first quartile, third quartile] difference, 0.5 [-1.0, 31.0] min; P = 0.87) or at the 6-month follow-up (7.0 [-9, 27] min; P = 0.16). CONCLUSIONS: Pedometer-directed step-count targets during an outpatient PR program did not enhance moderate-intensity physical activity levels in people with COPD. Clinical trial registered with www.clinicaltrials.gov (NCT01719822).