Health-related quality of life in chronic obstructive pulmonary disease patients in Korea

Table 2 EQ-5D index and EQ-VAS scores by GOLD criteria

	Crude mean	(SD)	P value^*	Adjusted mean^a	(SE)	P value^†	Grouping^b
EQ-5D index
Stage I, n = 13	0.83	0.17	<0.001	0.83	0.04	<0.001	A
Stage II, n = 114	0.88	0.12		0.88	0.02		A
Stage III, n = 59	0.82	0.16		0.81	0.03		A
Stage IV, n = 13	0.61	0.26		0.60	0.04		B
EQ-VAS
Stage I, n = 13	71.9	18.9	0.042	73.9	5.4	0.033	A
Stage II, n = 114	71.9	17.8		75.1	2.9		A
Stage III, n = 60	65.0	20.6		68.9	3.3		A
Stage IV, n = 13	60.9	13.9		65.1	5.6		A

SE, standard error of the mean.
^*Analysis of variance (ANOVA) tests of whether the four groups are equal.
^†Analysis of covariance (ANCOVA) tests of whether the four groups are equal.
^aMeans were adjusted by age group, level of education, gender, and smoking status.
^bDifferent alphabet (A, B) means a statistically significant difference group after Bonferroni correction. The same grouping was shown in both ANOVA and ANCOVA.

ISSN: 1477-7525