Effects of pulmonary rehabilitation in the functional status of people with ILD: a systematic review and meta-analysis

Abstract

Introduction: Interstitial lung diseases (ILD) are a disabling group of chronic respiratory diseases characterized by different degrees of lung inflammation and fibrosis. People with ILD frequently report a decline in their functional status with a significant impact on their daily life activities. Functional status is an individual’s ability to perform normal daily activities required to meet basic needs and maintain health and well-being. It includes functional capacity which refers to one’s maximal potential to realize a functional activity in a standardized environment and functional performance which refers to the activities people do during their daily life. Pulmonary rehabilitation (PR) has been shown to improve dyspnoea, exercise capacity and health-related quality of life in people with ILD, but its effects on the functional status of this population are widespread in the literature. Objectives: To synthesize the evidence of PR in the functional capacity and functional performance of people with ILD. Methods: A systematic review was conducted (CRD42022298584). Searches were performed in PubMed/MEDLINE, Scopus and Web of Science Core Collection databases for randomised controlled trials comparing PR with usual care in adults with ILD. Two independent reviewers assessed the titles, abstracts and full-texts according to the eligibility criteria, extracted and analyzed data and assessed the risk of bias with the Risk of Bias 2 tool. Results: Eight studies were included comprising 297 individuals with ILD (mean age range: PR group 45-71 years old; control group 40-72 years old) with severe to very severe lung function (DLCO% predicted mean range: PR group 44-67%pred; control group 37-64%pred). Functional capacity was assessed with the 6-minute walk test (6MWT) (n = 8), 30-second sit-to-stand test (30sec STS) (n = 1) and 6-minute stepper test (6MST) (n = 1). Functional performance was assessed with the number of daily steps, with a pedometer (n = 1) or SenseWear Armband (n = 1), and the international physical activity questionnaire (IPAQ) (n = 1). Significant improvements in functional capacity measured with the 6MWT (n = 201, MD 55.8 m, 95%CI [37.5; 74.1], p < 0.0001), the 30 sec STS (n = 32, MD 4.1 reps., 95%CI [2.3; 5.9], p < 0.0001) and the 6MST (n = 35, MD 69.0 steps, 95%CI [3.3; 134.7], p = 0.0394) were observed after PR compared with the control group. No statistically significant between-group differences in functional performance measures were observed. Conclusions: Pulmonary rehabilitation showed significant positive effects on the functional capacity but not on the functional performance of individuals with ILD. Measurements were mainly focused on the 6MWD, and few other functional status outcome measures have been included in PR programs. A more comprehensive assessment of this meaningful health domain to individuals with ILD, namely of their functional performance, which reflects what people do in their daily life, is fundamental to include in the routine assessment of PR, to identify needs and optimize care for this population.