Table 4– Pearson product–moment correlations between Capacity of Daily Living during the Morning (CDLM) or the Global Chest Symptoms Questionnaire (GCSQ) score and measures of lung function, symptoms and health status

	CDLM		GCSQ
	Study 1	Study 2	Study 1	Study 2
Subjects n	547	361	646	437
PEF morning	0.10*	0.11*	-0.12*	-0.16*
FEV₁ morning	0.01	0.03	-0.08	0.00
Total rescue	-0.37***	-0.17***	0.40***	0.20***
Breathlessness	-0.65***		0.73***
Cough	-0.43***		0.51
Chest tightness	-0.58***		0.81***
Sleep	-0.56***		0.58***
CCQ
Total		-0.61***		0.70***
Symptoms		-0.49***		0.65***
Function		-0.63***		0.65***
Mental		-0.53***		0.59***
SGRQ-C
Total	-0.55***	-0.49***	0.52***	0.35***
Symptoms	-0.32***	-0.16***	0.42***	0.27***
Activity	-0.57***	-0.43***	0.44***	0.26***
Impact	-0.47***	-0.48***	0.46***	0.33***

PEF: peak expiratory flow; FEV₁: forced expiratory volume in 1 s; CCQ: Clinical COPD Questionnaire; SGRQ-C: St George’s Respiratory Questionnaire for COPD patients. *: p<0.05; ***: p<0.001.