Psychometric performance of the CFQ-R-8D compared to the EQ-5D-3L and SF-6D in people with cystic fibrosis

Journal of Patient-Reported Outcomes

Table 1 Known-group validity based on clinical and demographic variables at baseline and follow-up in the EQ-5D-3L trials^a

		CFQ-R-8D				EQ-5D-3L
Variable	Groups	N	Mean	SD	ES^b	N	Mean	SD	ES^b
ppFEV₁—baseline	Normal ≥ 70%	246	0.842	0.11	0.31	246	0.920	0.14	0.09
	Mild 40 to < 70%	660	0.806	0.11	0.23	660	0.908	0.12	0.06
	Severe < 40%	80	0.78	0.13		80	0.900	0.12
			F(2,983) = 12.3				F(2,983) = 1.1
			P < 0.001				P = 0.34
ppFEV₁—24 weeks^c	Normal ≥ 70%	277	0.863	0.11	0.48	277	0.935	0.12	0.23
	Mild 40 to < 70%	579	0.802	0.13	0.42	579	0.903	0.15	0.35
	Severe < 40%	63	0.749	0.14		63	0.854	0.13
			F(2,916) = 33.8				F(2,916) = 10.6
			P < 0.001				P < 0.001
Pulmonary exacerbations—20–24 weeks (≥ 4)^c	No	835	0.825	0.12	0.60	835	0.917	0.13	0.44
	Yes	116	0.748	0.14		116	0.856	0.18
			t(949) = 6.3				t(949) = 4.5
			P < 0.001				P < 0.001
Age groups—baseline	14 to < 18 years	191	0.837	0.11	0.26	191	0.941	0.10	0.29
	≥ 18 years	806	0.807	0.12		806	0.903	0.14
			t(995) = 3.3				t(995) = 3.6
			P = 0.001				P < 0.001

CFQ-R-8D indicates Cystic Fibrosis Questionnaire–Revised–8 Dimensions; ES, effect sizes; ppFEV₁, percent predicted forced expiratory volume in 1 s
^a Pooled treatment and placebo arms
^b ES was calculated by comparing the utility values for adjacent subgroups in the clinical measures. Small ES ≥ 0.2 to < 0.5; medium ES ≥ 0.5 to < 0.8; large ES ≥ 0.8
^c 20–24 weeks and 24 weeks indicate follow-up at 20 to 24 weeks and follow-up at 24 weeks, respectively