Table 3.

Relationship between D6MWT or S6MWT and other parameters

Functional parameters	D6MWT (m)		S6MWT (step)
	ρ	P-value	ρ	P-value
Age (years)	−0.485	<0.001*	−0.229	0.057
Pre-6MWT IC (% predicted)	0.145	0.230	0.338	0.004*
Post-6MWT IC (% predicted)	0.160	0.189	0.359	0.002*
Pre-6MWT FVC (% predicted)	0.305	0.010*	0.363	0.002*
Post-6MWT FVC (% predicted)	0.267	0.025*	0.296	0.013*
Pre-6MWT FEV1 (% predicted)	0.330	0.005*	0.426	<0.001*
Post-6MWT FEV1 (% predicted)	0.310	0.009*	0.388	0.001*
Pre-6MWT FEV1/FVC (%)	0.373	0.001*	0.406	<0.001*
Post-6MWT FEV1/FVC (%)	0.293	0.014*	0.373	0.001*
Pre-6MWT SpO2 (%)	0.182	0.132	0.289	0.015*
Post-6MWT SpO2 (%)	0.245	0.041*	0.201	0.095
DLCO (% predicted)	0.411	<0.001*	0.548	<0.001*
RV/TLC (%)	−0.326	0.006*	−0.286	0.016*
R20 (kPa/L/s)	0.244	0.042*	0.171	0.157
X5 (kPa/L/s)	0.264	0.027*	0.336	0.004*
mMRC grade	−0.439	<0.001*	−0.451	<0.001*
SGRQ score	−0.332	0.005*	−0.344	0.004*
CCQ score	−0.435	<0.001*	−0.370	0.002*
CAT score	−0.393	0.001*	−0.431	<0.001*

^*Note: Statistical significance.

Abbreviations: CAT, Chronic Obstructive Pulmonary Disease Assessment Test; CCQ, Clinical Chronic Obstructive Pulmonary Questionnaire; D6MWT, distance of 6-minute walk test; DL_CO, diffusing capacity of the lungs for carbon monoxide; IC, inspiratory capacity; mMRC, modified Medical Research Council dyspnea scale; RV, residual volume; R₂₀, reactance at 20 Hz; S6MWT, steps of 6MWT; SGRQ, St George’s Respiratory Questionnaire; TLC, total lung capacity; ρ, correlation coefficient; X₅, reactance at 5 Hz.