Table 4

Longitudinal analysis of predictors of SDAI, CDAI, DAS28, HAQ-DI and EQ-5D utility values over time using a generalised estimating equation model among patients with RA who had never-used HRT and with a baseline SDAI>11

Outcome variable	Independent variables	Regression coefficient (β) (95% CI)	P value
SDAI	Age	0.011 (−0.029 to 0.050)	0.591
	RA duration	0.092 (0.049 to 0.135)	<0.001
	Baseline SDAI	0.591 (0.535 to 0.646)	<0.001
	Biologic use	0.463 (−0.862 to 1.787)	0.493
	Early menopause	1.212 (0.250 to 2.175)	0.014
	Follow-up time	−1.850 (−2.033 to −1.667)	<0.001
CDAI	Age	0.012 (−0.025 to 0.049)	0.531
	RA duration	0.096 (0.056 to 0.137)	<0.001
	Baseline CDAI	0.577 (0.522 to 0.632)	<0.001
	Biologic use	0.778 (−0.597 to 2.152)	0.267
	Early menopause	1.105 (0.229 to 1.980)	0.013
	Follow-up time	−1.756 (−1.925 to −1.587)	<0.001
DAS28	Age	0.003 (−0.003 to 0.010)	0.335
	RA duration	0.016 (0.009 to 0.023)	<0.001
	Baseline DAS28	0.617 (0.561 to 0.672)	<0.001
	Biologic use	0.236 (0.020 to 0.452)	0.032
	Early menopause	0.211 (0.053 to 0.369)	0.009
	Follow-up time	−0.311 (−0.339 to −0.283)	<0.001
HAQ-DI	Age	0.007 (0.004 to 0.010)	<0.001
	RA duration	0.011 (0.008 to 0.014)	<0.001
	Baseline HAQ-DI	0.682 (0.643 to 0.721)	<0.001
	Biologic use	0.040 (−0.054 to 0.134)	0.400
	Early menopause	0.099 (0.027 to 0.171)	0.007
	Follow-up time	0.000 (−0.014 to 0.014)	0.968
EQ-5D utility values	Age	−0.002 (−0.003 to −0.000)	0.008
	RA duration	−0.004 (−0.005 to −0.002)	<0.001
	Baseline EQ-5D utility value	0.537 (0.491 to 0.584)	<0.001
	Biologic use	−0.016 (−0.054 to 0.022)	0.405
	Early menopause	−0.031 (−0.061 to −0.001)	0.040
	Follow-up time	0.010 (0.005 to 0.016)	<0.001

All covariates adjusted in the model were listed as independent variables.
CDAI, Clinical Disease Activity Index; DAS28, Disease Activity Score using 28 joint counts; EQ-5D, EuroQol-5D; HAQ-DI, Health Assessment Questionnaire–Disability Index; SDAI, Simplified Disease Activity Index.