Generic utilities in chronic obstructive pulmonary disease patients stratified according to different staging systems

Table 4 Utility estimates by GOLD 2007, GOLD 2013, clinical phenotypes and BODEx index classification

		Utilities			p¹
		n (%)	Mean (SD)	Median (IQR)	p¹
GOLD 2007 ²	*COPD moderate*	135 (39.0%)	0.82 (0.22)	0.87 (0.22)	<0.001
	*COPD severe*	145 (41.9%)	0.72 (0.29)	0.80 (0.26)
	*COPD very-severe*	66 (19.1%)	0.57 (0.35)	0.66 (0.42)
GOLD 2013 ³	A	28 (8.1%)	0.96 (0.07)	1.00 (0.09)	<0.001
	B	66 (19.1%)	0.80 (0.22)	0.87 (0.13)
	C	30 (8.7%)	0.88 (0.25)	1.00 (0.16)
	D	222 (64.2%)	0.66 (0.31)	0.74 (0.29)
Clinical phenotype (GesEPOC)	*Non exacerbator*	207 (64.3%)	0.79 (0.24)	0.84 (0.33)	<0.001
	*COPD-asthma overlap*	21 (6.5%)	0.81 (0.20)	0.80 (0.26)
	*Exacerbator with emphysema*	41 (12.7%)	0.56 (0.42)	0.71 (0.62)
	*Exacerbator with chronic bronchitis*	53 (16.5%)	0.59 (0.36)	0.72 (0.57)
BODEx index classification	*0-2*	167 (48.3%)	0.85 (0.18)	0.89 (0.20)	<0.001
	*3-4*	93 (26.9%)	0.69 (0.29)	0.80 (0.27)
	*5-6*	75 (21.7%)	0.56 (0.35)	0.67 (0.29)
	*7-9*	11 (3.2%)	0.33 (0.30)	0.41 (0.31)

¹Kruskal-Wallis test and Mann–Whitney U test for post-hoc comparisons (Bonferroni-adjusted). Unilateral tests for pulmonary function, GesEPOC and BODEx index.
GOLD 2007: all pairwise comparisons were significant; GOLD 2013: all pairwise comparisons were significant, except for the comparison between groups A and C; Clinical phenotypes: differences between phenotypes A and C, A and D, and between B and D; BODEx index classification: all pairwise comparisons were significant except between the two groups with the greatest severity.
²COPD moderate: FEV₁/FVC < 0.70 and 50% ≤ FEV₁ < 80%*, COPD severe: FEV₁/FVC < 0.70 and 30% ≤ FEV₁ < 50%*, COPD very-severe: FEV₁/FVC < 0.70 y FEV₁ < 30%*. *respect to the reference value.
³A: low risk, few symptoms; B: low risk, many symptoms; C: high risk, few symptoms; D: high risk, many symptoms.
SD = standard deviation, IQR = interquartile range.

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