Table 3A.

Association between disability (HAQ) and DAS28, pain, and ES, from baseline to 1-year followup with GEE and multivariate model, controlled for sex, age, smoking habit, and duration for the separate cohorts.

Variables	Cohort 1			Cohort 2
Variables	β	95% CI	p	β	95% CI	p
DAS28	0.224	0.208–0.239	< 0.001	0.237	0.223–0.251	< 0.001
Female	0.111	0.045–0.177	0.001	0.180	0.118–0.241	< 0.001
Age, yrs	−0.001	−0.003 to 0.001	0.364	0.001	−0.001 to 0.003	0.339
Smoker	0.069	−0.006 to 0.144	0.072	0.126	0.053–0.199	0.001
Previous smoker	0.036	−0.038 to 0.109	0.340	0.084	0.017–0.152	0.014
Duration	−0.010	−0.020 to 0.000	0.053	0.994	0.986–1.002	0.147
Pain	0.014	0.013–0.015	< 0.001	0.015	0.014–0.016	< 0.001
Female	0.137	0.073–0.201	< 0.001	0.153	0.095–0.211	< 0.001
Age, yrs	0.002	−0.001 to 0.004	0.179	0.004	0.002–0.006	< 0.001
Smoker	0.017	−0.057 to 0.091	0.651	0.086	0.011–0.160	0.024
Previous smoker	−0.002	−0.075 to 0.070	0.948	0.052	−0.012 to 0.117	0.112
Duration	−0.011	−0.020 to −0.001	0.031	−0.010	−0.019 to 0.000	0.047
ES	−0.007	−0.012 to −0.001	0.013	−0.019	−0.027 to −0.004	< 0.001
Female	0.225	0.151–0.300	< 0.001	0.267	0.193–0.340	< 0.001
Age, yrs	0.001	−0.002 to 0.004	0.553	0.002	0.000–0.005	0.064
Smoker	0.079	−0.009 to 0.167	0.080	0.143	0.053–0.233	0.002
Previous smoker	0.034	−0.052 to 0.120	0.433	0.090	0.010–0.170	0.028
Duration	−0.010	−0.022 to 0.01	0.086	−0.013	−0.025 to −0.002	0.024

Significant data are in bold face. DAS28: 28-joint Disease Activity Score; ES: erosion score; HAQ: Health Assessment Questionnaire; GEE: generalized estimating equation.