Table 2

Spearman correlation coefficients* of D-PPAC and C-PPAC scores with dyspnoea, health-related quality of life, exercise capacity and objective physical activity level (convergent validity)

	D-PPAC						C-PPAC
	Amount		Difficulty		Total		Amount		Difficulty		Total
	Correlation	P value	Correlation	P value	Correlation	P value	Correlation	P value	Correlation	P value	Correlation	P value
mMRC	−0.20	<0.001	−0.40	<0.001	−0.40	<0.001	−0.40	<0.001	−0.64	<0.001	−0.65	<0.001
CRQ dyspnoea	0.16	0.006	0.68	<0.001	0.59	<0.001	0.28	0.045	0.61	<0.001	0.56	<0.001
CRQ fatigue	0.15	0.011	0.61	<0.001	0.52	<0.001	0.28	0.045	0.55	<0.001	0.51	<0.001
CRQ emotional	0.05	0.393	0.54	<0.001	0.41	<0.001	−0.20	0.028	−0.13	0.027	−0.18	0.008
CRQ mastery	0.08	0.143	0.53	<0.001	0.42	<0.001	0.00	0.989	0.64	<0.001	0.39	0.005
CCQ symptoms	−0.20	<0.001	−0.56	<0.001	−0.50	<0.001	−0.18	<0.001	−0.55	<0.001	−0.45	<0.001
CCQ functional	−0.36	<0.001	−0.77	<0.001	−0.74	<0.001	−0.34	<0.001	−0.76	<0.001	−0.69	<0.001
CCQ mental	−0.28	<0.001	−0.55	<0.001	−0.52	<0.001	−0.19	<0.001	−0.50	<0.001	−0.42	<0.001
CCQ total	−0.33	<0.001	−0.75	<0.001	−0.70	<0.001	−0.31	<0.001	−0.75	<0.001	−0.65	<0.001
CAT total	n.a.		n.a.		n.a.		−0.24	<0.001	−0.62	<0.001	−0.54	<0.001
6MWD	0.41	<0.001	0.40	<0.001	0.53	<0.001	0.49	<0.001	0.46	<0.001	0.53	<0.001
MVPA	0.67	<0.001	0.12	<0.001	0.53	<0.001	0.80	<0.001	0.30	<0.001	0.67	<0.001

*Correlation coefficients are in bold font when they met our assumptions (see online supplemental table S2 in the online data supplement) and normal font when they are higher or lower than expected.
CAT, chronic obstructive pulmonary disease assessment test; CCQ, clinical chronic obstructive pulmonary disease questionnaire; C-PPAC, Clinical visit version of PROactive Physical Activity in COPD instrument; CRQ, chronic respiratory questionnaire; D-PPAC, Daily version of PROactive Physical Activity in COPD instrument; mMRC, modified medical research council dyspnoea scale; MVPA, moderate-to-vigorous physical activity; 6MWD, 6 min walk distance; n.a, Not available.