Abstract
In COPD severity of disease is assessed with spirometry and dypnoea score such as CCQ (Clinical COPD Questionaire) or MRC (Medical Research Councel). Dyspnoea scores and spirometry are poorly correlated, dyspnoea may also be the result of other, not pulmonary aspects, especially in COPD GOLD 1 and 2.
Questions: 1. What is the predictive value of CCQ and MRC with respect to the degree and cause of exercise limitation in patients with COPD
2. Which factors predict a pulmonary limitation?
Methods: 60 symptomatic COPD patients in a stable phase without relevant comorbidity. At baseline they scored CCQ and MRC. A score of > 2 was considered abnormal dyspnoea (D +), others were D -. Exercise limitation in a cardiopulonary exercise test was labelled pulmonary (pulm), cardiac (card) or nonspecific (nonspec).
Results:
Main exercise limitating factor
D + patients had a higher BMI (p<0.05), lower FEV1% (p <0.01), a lower Wattmax, VO2max and Inspiratory Capacity (p<0.005).
In patients with a strict pulmonary limitation dyspnoea was not different from patients without pulmonary limitation. FEV1 and DLCO were significantly different, p<0.0001. Positive predictive value of dyspnoea score for pulmonary or cardiac limitation was 84% in all and 75% in patients with GOLD 1 and 2. Negative predictive value was 35% and 44% respectively.
Conclusions: In COPD patients GOLD 1 and 2 exercise limitation was not due to pulmonary factors in 86% and 43% of patients, respectively.
Pulmonary or cardiac limitation can be expected at high CCQ or MRC score, and can not be excluded in patients with a low score.
- © 2011 ERS
