Table 3

Regression with occurrence of IgA, IgG, IgM RF and ACPA positivity determined as any ACPA peptide reactivity evaluated together as independent variables and signs, symptoms or DAS28 evaluated individually as dependent variables

	IgA RF		IgG RF		IgM RF		Any ACPA peptide reactivity
	P value	β	P value	β	P value	β	P value	β
CRP (mg/L)	0.989	-0.0005	0.604	0.015	0.052	0.066	0.653	0.013
ESR (mm/ 1 hour)	0.010	0.084	0.059	0.054	0.011	0.085	0.522	0.018
SJC	0.304	−0.033	0.136	0.043	0.686	−0.014	0.0003	−0.104
TJC	0.805	−0.008	0.856	0.005	0.720	−0.012	0.0003	−0.106
DAS28	0.963	0.002	0.218	0.037	0.155	0.049	0.084	−0.051
DAS28CRP	0.076	−0.059	0.339	0.028	0.166	0.048	0.016	−0.072
Patient global VAS	0.108	−0.053	0.885	−0.004	0.034	0.073	0.173	−0.041
HAQ	0.478	0.024	0.454	0.022	0.927	0.003	0.565	−0.017

The models are adjusted for age, sex, inclusion year and symptom duration. Statistically significant associations are depicted in bold. The corresponding analysis with ACPA positivity determined as anti-CCP2 status is found in online supplemental table 3.
ACPA, antibodies against citrullinated protein; CRP, C-reactive protein; DAS28, 28-joint disease activity scores; ESR, erythrocyte sedimentation rate; HAQ, Health Assessment Questionnaire; IgA, immunoglobulin A; RA, rheumatoid arthritis; RF, rheumatoid factor; SJC, swollen joint count; TJC, tender joint count; VAS, visual analogue scale; β, standardised beta coefficient.