A Feasibility Study of a Randomized Controlled Trial of Asthma-Tailored Pulmonary Rehabilitation Compared with Usual Care in Adults with Severe Asthma

Background: Currently, the acceptability and efficacy of pulmonary rehabilitation for adults with severe asthma is unknown.

Objective: To investigate the feasibility of performing a randomized controlled trial of asthma-tailored pulmonary rehabilitation (AT-PR) versus usual care (UC).

Methods: Adults with severe asthma were recruited and randomized 2:1 to AT-PR and UC. The primary outcomes were recruitment, retention, and serious adverse event rates. Secondary outcome measures included those for a future trial assessing the feasibility of collecting data. Assessments were performed at baseline, 12 weeks, and 9 months including measures of physical performance, health-related quality of life, and asthma control. A recruitment rate of 30% was estimated with 95% CI of ±7%, a retention rate of 75% ± 14% if we recruited 40 patients to AT-PR, and a serious adverse event rate of 2.5%.

Results: Sixty-one (26%) of 238 eligible patients were recruited (38 women; mean age, 54 ± 13 years; body mass index, 32 ± 7 kg/m²; FEV₁, 1.9 ± 0.7 L; FEV₁/forced vital capacity, 69% ± 11%). Fifty-one patients were randomized to AT-PR (n = 34) and UC (n = 17). The retention rate was 62% for the AT-PR group and 53% for the UC group, with a serious adverse event rate of 3.3% related to the study visits. Overall collection of the outcome measures was feasible. The results of the AT-PR group were suggestive of improvements in exercise performance, health-related quality of life, and asthma control, but the UC group results were either unchanged or worsened.

Conclusions: Both recruitment and retention rates were within the a priori estimated 95% CI. Our results indicate that AT-PR may be efficacious for adults with severe asthma but any future intervention and trial design would need further modifications to improve acceptability and retention rate.