Designing trials of behavioral interventions to increase physical activity in patients with COPD: insights from the chronic disease literature

Abstract

Objectives: There is increasing evidence that physical activity (PA) can affect health outcomes, particularly in chronic disease. While pharmacologic therapy and exercise training can improve exercise capacity, increasing PA requires behavior change. This review examined clinical trials testing the effectiveness of behavioral interventions to increase PA in adults with chronic disease to inform future research in COPD.

Methods: Embase and PubMed searches of studies published in English, 1995-2011.

Inclusion criteria: Adults ≥ 45 years; COPD, diabetes, heart failure, obesity; exercise or PA endpoint; behavioral intervention described in sufficient detail to permit interpretation.

Results: 932 abstracts screened; 169 articles retrieved; 36 reviewed. Most were randomized trials (n = 32, 89%); 2 arms (n = 26, 72%), sample sizes 40-100 (n = 15, 42%); recruitment through clinical settings (n = 28, 78%); disease severity as primary eligibility criterion (n = 23, 64%); mean duration: 10 months (range: 1-84). Exercise intervention: aerobic activity, 30-60 min (n = 20, 56%), 3-5 times/week (n = 20, 56%). Behavioral intervention: Counseling (n = 19, 53%) with personal follow-up (n = 12, 33%).

Control group: Exercise without behavioral intervention (n = 14, 39%) or usual care (n = 15, 42%). Significant effects were reported in 15 of 25 (60%) studies testing exercise capacity (6-minute walk, cycle, treadmill), 19 of 26 (73%) testing PA (pedometer, activity log, questionnaire), 11 of 22 (50%) measuring quality of life, and 8 of 13 (62%) capturing behavioral endpoints.

Conclusions: This review provides insight into the range of designs, interventions, and outcome measures used in studies testing methods to improve PA in chronic disease with implications for designing trials in COPD.

Keywords: Activity outcomes; Behavioral interventions; COPD; Literature review; Physical activity; Trial design.