Adherence to singing training vs. physical training in COPD rehabilitation: Post hoc analyses from the Sing-a-Lung trial

Background: Pulmonary rehabilitation (PR) is a cornerstone in COPD care, however, maintaining high adherence rates can be challenging. In the Sing-a-Lung multicentre randomised controlled trial, we demonstrated that singing training was as efficacious as physical training in improving 6-Minutes Walk Test (6MWT) and superior concerning quality of life1. There is no knowledge about the impact of adherence on change in 6MWT and St George’s Respiratory Questionnaire (SGRQ), and factors related to high adherence to singing training vs. physical training.
Methods: Post hoc analyses of the Sing-a-Lung trial (of the effects of singing training compared to physical training in a 10 weeks’ PR program for COPD patients). Multivariable logistic regression analysing 1) the relationship between adherence (low: 0-49% attendance; medium: 50-74%; high: 75-100%) and achieving a significant improvement of 6MWT (30 meters) and SGRQ total score (4 points) from baseline to post-PR, and 2) factors related to high adherence. The regression models included baseline characteristics, COPD severity, and expectations towards singing.
Results: 270 patient were included in Sing-a-Lung. Number of patients with high adherence was similar in the two study arms (physical training 71 [56.8%], singing training 88 [60.7%], p=0.90). Patients with medium and high adherence had significantly higher odds for improving 6MWT (OR 5.6 [95%CI 1.4-22.4], p=0.02; and OR 10.5 [3.0-36.6], p<0.001, respectively) and SGRQ (OR 8.3 [2.1-32.7], p=0.003; and OR 17.0 [4.9-58.3], p<0.001, respectively) with low adherence as reference. There was no significant factors related adherence.
Conclusions: There was a similar dose-response relationship between adherence and improvement of 6MWT and SGRQ, and adherence were similar for singing training and physical training.

1. Kaasgaard M, et al. Sing-a-Lung: Group singing as training modality in pulmonary rehabilitation for patients with Chronic Obstructive Pulmonary Disease (COPD): A multicenter, cluster-randomised, non-inferiority controlled trial. Abstract 4663, ERS International Virtual Congress 2020, 7-9 Sept.