The relation of the subjective dyspnoea perception with objective dyspnoea indicators, quality of life and functional capacity in patients with COPD

Aims and objectives. The study was conducted to determine the relationship between the subjective dyspnoea perception and objective dyspnoea indicators, quality of life and functional capacity. Background. Even though dyspnoea severity is generally assessed through objective parameters such as respiratory functions and arterial blood gases, studies indicate that subjectively perceived dyspnoea is not always consistent with objective dyspnoea indicators. For that reason, it is necessary to assess the changes caused by dyspnoea on quality of life and on functional capacity in addition to objective dyspnoea indicators to assess subjective dyspnoea in the most accurate way in patients with COPD. Design. A correlational study. Methods. The subjective dyspnoea was evaluated via the Basal Dyspnea Index and Visual Analog Scale, whereas objective dyspnoea was evaluated through respiratory function tests and arterial blood gases, which are physiological measurements. The quality of life was assessed with SF-36 and St. George's Respiratory Diseases Questionnaire. Functional capacity was evaluated with the six-minute walking distance test. Results. Basal Dyspnea Index score was associated with respiratory functions (FEV1, FVC, FEV1/FVC), arterial blood gases (SaO2, PaO2, pH), the quality of life and functional capacity, while Visual Analog Scale score was not associated with these measurements. Conclusions. Subjective dyspnoea severity assessed by Basal Dyspnea Index is related to the objective dyspnoea indicators, quality of life and functional capacity. In the assessment of dyspnoea, Basal Dyspnea Index is an appropriate measure, whereas Visual Analog Scale is not. In the light of these results, we recommend that Basal Dyspnea Index should be used in the assessment of dyspnoea in patients with COPD. Relevance to clinical practice. We conclude that dyspnoea will be evaluated in the most accurate and short way with the Basal Dyspnea Index. In addition, the effects of dyspnoea on quality of life and functional capacity will be predicted by Basal Dyspnea Index.