Mood disorder in idiopathic pulmonary fibrosis: response to pulmonary rehabilitation

Background: Pulmonary rehabilitation improves mood disorder in COPD, but there are limited data in idiopathic pulmonary fibrosis (IPF). The aims of this cohort study were to investigate whether pulmonary rehabilitation reduces mood disorder in IPF, and estimate the minimal important difference (MID) of the Hospital Anxiety and Depression Scale (HADS). Methods: HADS and core pulmonary rehabilitation outcomes were measured in 166 participants before and after an 8-week, in-person, outpatient pulmonary rehabilitation programme. Anchor- and distribution-based methods were used to calculate the MID of HADS-Anxiety (A) and HADS-Depression (D). Results: Suggestive or probable anxiety and depression (HADS ≥8) were present in 35% and 37% of participants, respectively, at baseline, and this reduced significantly following pulmonary rehabilitation (post-pulmonary rehabilitation: HADS-A 23%, HADS-D 26%). Overall, there was a significant reduction in HADS-D (mean change -1.1, 95% CI -1.6- -0.5), but not HADS-A (-0.6, -1.3-0.15) with pulmonary rehabilitation. Subgroup analysis of those with HADS ≥8 revealed significant improvements in HADS domains (mean change: HADS-A -4.5, 95% CI -5.7- -3.4; median change: HADS-D -4.0, interquartile range -6.0- -1.0). The mean (range) MID estimates for HADS-A and HADS-D were -2 (-2.3- -1.7) and -1.2 (-1.9- -0.5), respectively. Conclusion: In people with IPF and suggestive or probable mood disorder, pulmonary rehabilitation reduces anxiety and depression.