Pulmonary rehabilitation for interstitial lung disease

Interstitial lung disease (ILD) is characterised by reduced functional capacity, dyspnoea and exercise-induced hypoxia. Pulmonary rehabilitation, an intervention that includes exercise training, is beneficial for people with other chronic lung conditions; however its effects in ILD have not been well characterised.

• To determine whether pulmonary rehabilitation in patients with ILD has beneficial effects on exercise capacity, symptoms, quality of life and survival compared with no pulmonary rehabilitation in patients with ILD.• To assess the safety of pulmonary rehabilitation in patients with ILD.

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 6), MEDLINE (Ovid), EMBASE (Ovid), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCO) and the Physiotherapy Evidence Database (PEDro) (all searched from inception to June 2014). We also searched the reference lists of relevant studies, international clinical trial registries and respiratory conference abstracts to look for qualifying studies.

Randomised and quasi-randomised controlled trials in which pulmonary rehabilitation was compared with no pulmonary rehabilitation or with other therapy in people with ILD of any origin were included.

Two review authors independently selected trials for inclusion, extracted data and assessed risk of bias. Study authors were contacted to provide missing data and information regarding adverse effects. A priori subgroup analyses were specified for participants with idiopathic pulmonary fibrosis (IPF) and participants with severe lung disease (low diffusing capacity or desaturation during exercise). We planned to subgroup according to training modality applied, but there were insufficient data.

Nine studies were included, six of which were published as abstracts. Five studies were included in the meta-analysis (86 participants who undertook pulmonary rehabilitation and 82 control participants). One study used a blinded assessor and intention-to-treat analysis. No adverse effects of pulmonary rehabilitation were reported. Pulmonary rehabilitation improved the six-minute walk distance with weighted mean difference (WMD) of 44.34 metres (95% confidence interval (CI) 26.04 to 62.64 metres) and improved oxygen consumption (VO2) peak with WMD of 1.24 mL/kg/min(-1) (95% CI 0.46 to 2.03 mL/kg/min(-1)). Improvements in six-minute walk distance and VO2 peak were also seen in the subgroup of participants with idiopathic pulmonary fibrosis (IPF) (WMD 35.63 metres, 95% CI 16.02 to 55.23 metres; WMD 1.46 mL/kg/min(-1), 95% CI 0.54 to 2.39 mL/kg/min(-1), respectively). Reduced dyspnoea (standardised mean difference (SMD) -0.66, 95% CI -1.05 to -0.28) following pulmonary rehabilitation was also seen in the IPF subgroup (SMD -0.68, 95% CI -1.12 to -0.25). Quality of life improved following pulmonary rehabilitation for all participants on a variety of measures (SMD 0.59, 95% CI 0.20 to 0.98) and for the subgroup of people with IPF (SMD 0.59, 95% CI 0.14 to 1.03). Two studies reported longer-term outcomes, with no significant effects of pulmonary rehabilitation on clinical variables or survival at three or six months. Available data were insufficient to allow examination of the impact of disease severity or exercise training modality.

Pulmonary rehabilitation seems to be safe for people with ILD. Improvements in functional exercise capacity, dyspnoea and quality of life are seen immediately following pulmonary rehabilitation, with benefits also evident in IPF. Because of inadequate reporting of methods and small numbers of included participants, the quality of evidence was low to moderate. Little evidence was available regarding longer-term effects of pulmonary rehabilitation.