Plasma interferon-alpha is associated with double-positivity for autoantibodies but is not a predictor of remission in early rheumatoid arthritis—a spin-off study of the NORD-STAR randomized clinical trial

Table 3 Factors associated with IFNα positivity at day 1 and week 24

	OR for IFNα positivity at day 1^a	95% CI	OR for IFNα positivity at week 24^a	95% CI
RF+ACPA+^b	8.92	4.21–22.04	5.24	2.02–17.95
Current smoker^b	1.70	0.91–3.15	2.18	1.01–4.56
CDAI day 1^c	1.02	1.00–1.04	1.03	1.00–1.06
CRP day 1^d	1.00	0.99–1.01	1.00	0.98–1.01

Multivariable logistic regression with IFNα positivity at day 1 and week 24 as the dependent variable. At day 1, IFNα-positive (n = 91) and IFNα-negative (n = 255). At week 24, IFNα-positive (n = 41) and IFNα-negative (n = 305)
RF rheumatoid factor, ACPA anti-citrullinated protein antibodies, CDAI clinical disease activity index
^aIFNα positivity defined as IFNα protein level above 136 fg/mL
^bYes versus no
^cPer point increase
^dPer 1 mg/L increase

ISSN: 1478-6362