Table 4.

Correlations between gas trapping measures and quantitative outcomes in subjects with severe emphysema (Insp_-950HU > 15% ex-smokers, Insp_-950HU > 14% current smokers)

			Correlations
	N	Mean (SD)	Exp−856	E/I MLA	RVC856-950	Residual
FEV1 % predicted	1185	41.2 (19.9)	−0.69‡	−0.73‡	−0.73‡	−0.16‡
FVC % predicted	1185	75.7 (21.1)	−0.49‡	−0.56‡	−0.57‡	−0.17‡
FEV1/FVC	1185	0.40 (0.12)	−0.66‡	−0.62‡	−0.62‡	−0.08*
FEF25-75	1185	0.42 (0.38)	−0.56‡	−0.61‡	−0.61‡	−0.18‡
FRC/TLC ratio	1188	0.69 (0.12)	0.80*	0.93*	0.87*	0.44*
6MWD	1135	1116 (404)	−0.31‡	−0.40‡	−0.43‡	−0.01NS
Exacerbation frequency	1188	0.8 (1.2)	0.10†	0.12‡	0.13‡	−0.02NS
SGRQ total	1188	44.9 (19.9)	0.32‡	0.41‡	0.43‡	0.09*
MMRC dyspnea	1183	2.5 (1.3)	0.34‡	0.38‡	0.42‡	0.01NS

Pearson correlation coefficients are shown.

*p < 0.01.

†p < 0.001.

‡p < 0.0001.

NS = not significant (p > 0.05).