Association of anti-peptidyl arginine deiminase antibodies with radiographic severity of rheumatoid arthritis in African Americans

Table 2 Unadjusted and adjusted zero-inflated negative binomial models to evaluate the association of anti-PAD4 or anti-PAD4/PAD3 positivity with total radiographic scores for CLEAR I and CLEAR II patients at baseline (cross-sectional analysis) (N = 192)

Predictor/variable	Each variable combined with disease duration (BL) (IRR; 95 % CI)	Multivariable^a (BL) (IRR; 95 % CI)	P value (multivariable model)
Anti-CCP model
Anti-CCP	3.87 (1.90, 7.89)	4.48 (2.15, 9.36)	<0.001
RA disease duration (per 6 months)	1.05 (1.03, 1.07)	1.06 (1.04, 1.08)	<0.001
Smoking (reference to never smoker)
Current	1.36 (0.73, 2.50)	1.22 (0.67, 2.25)	0.517
Former	0.75 (0.39, 1.44)	0.57 (0.29, 1.20)	0.093
Anti-PAD4 model
Anti-PAD4	1.25 (0.71, 2.22)	1.76 (0.89, 3.46)	0.102
RA disease duration (per 6 months)	1.05 (1.03, 1.07)	1.05 (1.03, 1.07)	<0.001
Smoking (reference to never smoker)
Current	1.36 (0.73, 2.50)	1.40 (0.76, 2.58)	0.284
Former	0.75 (0.39, 1.44)	0.54 (0.25, 1.15)	0.110
Anti-PAD4/PAD3 model
Anti-PAD4/PAD3 cross-reactivity	1.88 (0.88, 4.03)	2.63 (1.16, 5.95)	0.020
RA disease duration (per 6 months)	1.05 (1.03, 1.07)	1.06 (1.04, 1.08)	<0.001
Smoking (reference to never smoker)
Current	1.36 (0.73, 2.50)	1.30 (0.71, 2.38)	0.403
Former	0.75 (0.39, 1.44)	0.50 (0.25, 1.00)	0.049

RA medication and age were not significantly associated with the outcome in the bivariable model and therefore were not included in the multivariable model
^aMultivariable model adjusted for all the variables included in the table
PAD peptidyl arginine deiminase enzyme, CLEAR Consortium for the Longitudinal Evaluation of African Americans with Early Rheumatoid Arthritis, BL baseline data, IRR incidence rate ratio, CI confidence interval, RA rheumatoid arthritis
P values less than 0.05 are shown in bold

ISSN: 1478-6362