Table 8.
Spearman rank correlations between health status questionnaires (CAT and CCQ), lung function, exacerbation frequency in the previous year, and mMRC dyspnea scale at baseline (n=372)
| Variables | CAT | CCQ total | CCQ symptom | CCQ function | CCQ mental | mMRC | FEV1% predicted | Exacerbation frequency |
|---|---|---|---|---|---|---|---|---|
| CAT | – | 0.776** | 0.590** | 0.688** | 0.409** | 0.614** | −0.270** | 0.516** |
| CCQ total | – | – | 0.734** | 0.829** | 0.628** | 0.540** | −0.271** | 0.542** |
| CCQ symptom | – | – | – | 0.497** | 0.273** | 0.346** | −0.271** | 0.439** |
| CCQ function | – | – | – | – | 0.334** | 0.578** | −0.321** | 0.468** |
| CCQ mental | – | – | – | – | – | 0.284** | −0.132* | 0.339** |
| mMRC | – | – | – | – | – | – | −0.315** | 0.342** |
| FEV1% predicted | – | – | – | – | – | – | – | −0.280** |
| Exacerbation frequency | – | – | – | – | – | – | – | – |
Notes:
**
P<0.01,
*
P<0.05.
Abbreviations: CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire; FEV1, forced expiratory volume in 1 second; mMRC, modified Medical Research Council dyspnea score.