Assessing health status in COPD. A head-to-head comparison between the COPD assessment test (CAT) and the clinical COPD questionnaire (CCQ)

Table 2 Spearman rank correlations between health status questionnaires (CAT, CCQ, SGRQ), lung function, GOLD stage, MRC dyspnea scale, 6MWT and BODE-index at baseline

	CAT	CCQ Total	CCQ Symptom	CCQ Mental	CCQ Functional	SGRQ Total	SGRQ Symptom	SGRQ Activity	SGRQ Impact	GOLD stage	FEV1% pred
CAT	1	0.644**	0.540**	0.438**	0.616**	0.646**	0.404**	0.629**	0.662**	0.337**	−0.353**
CCQ
Total	0.644**	1	0.867**	0.700**	0.932**	0.769**	0.502**	0.711**	0.703**	0.361**	−0.410**
Symptom	0.540**	0.867**	1	0.542**	0.690**	0.629**	0.584**	0.516**	0.590**	0.275**	−0.286**
Mental	0.438**	0.700**	0.542**	1	0.557**	0.529**	0.463**	0.448**	0.453**	0.222*	−0.298**
Functional	0.616**	0.932**	0.690**	0.557**	1	0.733**	0.366**	0.753**	0.660**	0.376**	−0.421**
SGRQ
Total	0.646**	0.769**	0.629**	0.529**	0.733**	1	0.602**	0.830**	0.964**	0.474**	−0.487**
Symptom	0.404**	0.502**	0.584**	0.463**	0.366**	0.602**	1	0.322**	0.533**	0.357**	−0.357**
Activity	0.629**	0.711**	0.516**	0.448**	0.753**	0.830**	0.322**	1	0.740**	0.388**	−0.403**
Impact	0.662**	0.703**	0.590**	0.453**	0.660**	0.964**	0.533**	0.740**	1	0.450**	−0.443**
MRC	0.605**	0.739**	0.518**	0.435**	0.784**	0.690**	0.360**	0.736**	0.627**	0.372**	−0.437**
dyspnea
Scale
6MWT	−0.205(ns)	−0.239*	−0.170 (ns)	−0.071(ns)	−0.302**	−0.281**	−0.054 (ns)	−0.365**	−0.264*	−0.255*	0.216**
BODE-index	0.483**	0.556**	0.433**	0.347**	0.545**	0.609**	0.413**	0.524**	0.577**	0.732**	−0.705**

*Correlations are significant at the 0.05 level ** Correlations are significant at the 0.01 level. ns = not significant. Lung function is expressed as FEV1%predicted. CAT = COPD assessment Test. CCQ = Clinical COPD Questionnnaire. SGRQ = St. George Respiratory Questionnaire. 6MWT = 6-minute walking test. MRC = Medical Research Council dyspnoea scale, BODE = body mass index, airflow limitation (forced expiratory volume in one second), dyspnoea and 6-min walk distance.

ISSN: 1471-2466