Relevance of multidimensional dyspnea assessment in the context of pulmonary rehabilitation.

Objectives: While dyspnea is the main symptom in chronic obstructive pulmonary disease (COPD), it is often inadequately evaluated in pulmonary rehabilitation (PR), as it is typically measured using only the impact dimension (ID). However, dyspnea is a multidimensional construct including perception (PD) and emotional (ED) domains. Our work aimed to study the complementarity of dyspnea dimensions and their respective ability to identify different evolutions during PR. Methods: 145 people with COPD attending PR were included in this retrospective study. Dyspnea scores from the modified Medical Research Council scale (ID) and the Multidimensional Dyspnea Profile questionnaire (PD/ED), exercise capacity, quality of life at the start (T1) and the end of PR (T2) were collected from existing databases/medical files. The evolution of each dyspnea dimension was evaluated using the delta score between T2-T1. PR response was defined using the minimal clinically important difference. Results: Our results show that each dyspnea dimension was associated with different health-outcomes. Positive correlations were found between PD-ED at baseline and between their T2-T1 delta score (ρ = 0.51; ρ = 0.41 respectively, p < .01), but there was no significant correlation between ID-PD or -ED (p > .05). 51% of the patients did not respond on ID, but 85% of them nonetheless responded on either PD or ED. Finally, 92% of patients responded on at least one dimension after PR. Discussion: Our study emphasizes the significance of assessing each dimension of dyspnea independently and complementary, as dimensions are associated with different elements and evolve differently under PR effects. This approach is crucial to identifying weak points and allows professionals to focus on program elements that most effectively address the specific dimension causing problems.