Performance of the Dutch SF-36 version 2 as a measure of health-related quality of life in patients with rheumatoid arthritis

Table 4 Convergent/discriminant validity and known-groups validity of the SF-36v2 scales and summary scores (N = 387)

	Spearman correlations at 6 month					Mean (SD) scores across levels of disease activity at 6 months
	HAQ-DI	PGA	TJC	SJC	ESR	Low disease activity	Moderate-high	F(1, 331)	P
	(n = 378)	(n = 338)	(n = 338)	(n = 338)	(n = 337)	(DAS28 ≤3.2)	disease activity
						(n = 232)	(n = 101)
PF	−0.76	−0.49	−0.36	−0.17	−0.13	73.56 (23.29)	52.87 (23.51)	55.18	<0.001
RP	−0.58	−0.54	−0.32	−0.19	0.02	65.46 (26.24)	43.19 (24.18)	53.11	<0.001
BP	−0.64	−0.65	−0.44	−0.29	−0.09	70.86 (18.39)	47.58 (17.28)	116.89	<0.001
GH	−0.43	−0.46	−0.24	−0.05	−0.08	63.41 (18.46)	48.85 (17.85)	44.60	<0.001
VT	−0.47	−0.47	−0.21	−0.06	−0.05	63.47 (19.10)	50.19 (18.51)	34.67	<0.001
SF	−0.51	−0.45	−0.24	−0.10	−0.01	83.73 (20.06)	69.93 (22.58)	30.83	<0.001
RE	−0.47	−0.44	−0.13	−0.05	−0.04	75.32 (26.20)	58.66 (29.20)	26.52	<0.001
MH	−0.34	−0.32	−0.13	−0.05	−0.00	77.84 (17.99)	70.00 (20.00)	12.49	<0.001
PCS	−0.71	−0.58	−0.44	−0.24	−0.12	45.77 (8.40)	36.48 (7.45)	91.97	<0.001
MCS	−0.33	−0.34	−0.07	−0.00	−0.05	50.72 (10.51)	46.16 (12.05)	12.07	0.001

PF, Physical functioning; RP, Role-physical; BP, Bodily pain; GH, General health; VT, Vitality; SF, Social functioning; RE, Role-Emotional; MH, Mental health; HT, Health transition; PCS, Physical component summary; MCS, Mental component summary; HAQ-DI, Health assessment questionnaire disability index; PGA, Patient global assessment of well-being; visual analog scale for general health; TJC, Tender joint count; SJC, Swollen joint count; ESR, Erythrocyte sedimentation rate.

ISSN: 1477-7525