Effectiveness of a Long-term Home-Based Exercise Training Program in Patients With COPD After Pulmonary Rehabilitation: A Multicenter Randomized Controlled Trial

Abstract

Background: Most patients with COPD do not maintain exercise training after pulmonary rehabilitation (PR).

Research question: Does a 12-month home-based, minimal-equipment strength training program after PR have an effect on dyspnea, exercise capacity, and patient-reported outcomes in patients with COPD?

Study design and methods: In a parallel-arm multicenter study across four Swiss PR clinics, patients with COPD were allocated randomly (1:1 ratio) into an intervention group (IG; home-based strength training program) or control group (CG; usual care). The primary outcome was change in Chronic Respiratory Questionnaire (CRQ) dyspnea scale score from baseline to 12 months. Secondary outcomes were change in exercise capacity (1-min sit-to-stand-test [1MSTST], 6-min walk test [6MWT]), health-related quality of life, exacerbations, and symptoms. We assessed the IG's experience by interviews at study end. Main analyses were based on the intention-to-treat approach, and adjusted linear regression models were used.

Results: One hundred twenty-three patients with COPD (IG, n = 61; CG, n = 62) were randomized, 61 of whom were women and whose mean ± SD age was 66.8 ± 8.1 years and mean ± SD FEV₁ was 39.3 ± 15.3% predicted. One hundred four participants completed 12 months of follow-up (IG, n= 53; CG, n= 51). Of the 53 IG participants, 37 participants (70%) conducted the training until study end. We found no difference in change in CRQ dyspnea scale score over 12 months (adjusted mean difference, 0.28; 95% CI, -0.23 to 0.80; P = .27). We found moderate evidence for a difference in 1MSTST repetitions favoring the IG (adjusted mean difference, 2.6; 95% CI, 0.22-5.03; P = .033), but no evidence for an effect in other outcomes. Seventy-nine percent of the IG reported positive effects that they attributed to the training.

Interpretation: The home exercise program had no effect on dyspnea, but improved 1MSTST performance and patient-perceived fitness. The supported program was well accepted by patients with COPD and may facilitate continued exercise training at home.

Trial registry: ClinicalTrials.gov; No.: NCT03461887; URL: www.

Clinicaltrials: gov.

Keywords: COPD; dyspnea; effectiveness; functional exercise capacity; home-based exercise training; long-term maintenance; minimal equipment; pulmonary rehabilitation; quality of life; randomized controlled trial.