Agreement between Breathlessness Severity and Unpleasantness in People with Chronic Breathlessness: A Longitudinal Clinical Study.

BACKGROUND: Chronic breathlessness is a cardinal symptom in cardiopulmonary disease where both overall intensity or severity (S) and unpleasantness (U) are commonly quantified. We aimed to evaluate agreement between breathlessness severity and unpleasantness over eight days in patients with chronic breathlessness.

METHODS: Longitudinal analysis of 265 patients with chronic breathlessness who rated current overall breathlessness severity and unpleasantness on 0-100mm visual analogue scales (VAS) in the morning and evening over eight days. A total 3,630 paired overall severity-unpleasantness (S-U) differences were analyzed; median 15 (IQR 13-16) per patient. Agreement was evaluated using Bland-Altman plots. Associations of the S-U difference with clinical factors and perceived quality of life were analyzed using multi-level linear regression adjusted for confounders.

RESULTS: Over eight days, severity and unpleasantness scores were highly correlated, had similar variability and varied more between than within patients. The mean S-U difference was small at 2.1 mm. Agreement between overall severity and unpleasantness was similar or higher than expected from the variability in individual scores. The S-U difference was similar across evaluated factors including age, sex, diagnosis, morning/evening assessment, modified Medical Research Council (mMRC) breathlessness score, morphine treatment and presence of different sensory qualities of breathlessness. Higher overall severity and unpleasantness associated with worse perceived quality of life in a similar way.

CONCLUSION: In patients with chronic breathlessness over eight days, overall severity and unpleasantness of breathlessness was comparable and associated to other clinical factors in a similar manner.