Effects of exercise-based pulmonary rehabilitation on adults with asthma: a systematic review and meta-analysis

BACKGROUND: Pulmonary rehabilitation (PR) has been proposed as an effective method for many respiratory diseases. However, the effects of exercise-based PR on asthma are currently inconclusive. This review aimed to investigate the effects of exercise-based PR on adults with asthma. METHODS: The PubMed, Embase, Cochrane Library, Web of Science, International Clinical Trials Registry Platform and ClinicalTrials.gov databases were searched from inception to 31 July 2019 without language restriction. Randomized controlled trials (RCTs) investigating the effects of exercise-based PR on adults with asthma were included. Study selection, data extraction and risk of bias assessment were performed by two investigators independently. Meta-analysis was conducted by RevMan software (version 5.3). Evidence quality was rated by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. RESULTS: Ten literatures from nine studies (n = 418 patients) were identified. Asthma quality of life questionnaire total scores (MD = 0.39, 95% CI: 0.02 to 0.76) improved significantly in the experimental group compared to control group, including activity domain scores (MD = 0.58, 95% CI: 0.21 to 0.94), symptom domain scores (MD = 0.52, 95% CI: 0.19 to 0.85), emotion domain scores (MD = 0.53, 95% CI: − 0.03 to 1.09) and environment domain scores (MD = 0.56, 95% CI: 0.00 to 1.11). Both the 6-min walk distance (MD = 34.09, 95% CI: 2.51 to 65.66) and maximum oxygen uptake (MD = 4.45, 95% CI: 3.32 to 5.58) significantly improved. However, improvements in asthma control questionnaire scores (MD = − 0.25, 95% CI: − 0.51 to 0.02) and asthma symptom-free days (MD = 3.35, 95% CI: − 0.21 to 6.90) were not significant. Moreover, there was no significant improvement (MD = 0.10, 95% CI: − 0.08 to 0.29) in forced expiratory volume in 1 s. Nonetheless, improvements in forced vital capacity (MD = 0.23, 95% CI: 0.08 to 0.38) and peak expiratory flow (MD = 0.39, 95% CI: 0.21 to 0.57) were significant. CONCLUSIONS: Exercise-based PR may improve quality of life, exercise tolerance and some aspects of pulmonary function in adults with asthma and can be considered a supplementary therapy. RCTs of high quality and large sample sizes are required. Clinical trial registration: The review was registered with PROSPERO (The website is https://www.crd.york.ac.uk/prospero/, and the ID is CRD42019147107).