Table 3.

Multivariable model showing interaction between race and rheumatic diagnosis (RA or SLE) for the risk of preterm birth compared to the general population

	SLE vs. General Population		RA vs. General Population
	Unadjusted RR	Adjusted RR	Unadjusted RR	Adjusted RR
NH Black vs. NH White	0.94 (0.74, 1.18)	0.94 (0.74, 1.20)	1.42 (1.03, 1.95)	1.38 (1.00, 1.91)
NH Black vs. Hispanic	0.80 (0.65, 0.98)	0.82 (0.65, 1.02)	1.73 (1.26, 2.37)	1.65 (1.20, 2.28)
NH Black vs. Asian	0.80 (0.63, 1.03)	0.82 (0.63, 1.06)	1.24 (0.81, 1.90)	1.29 (0.83, 2.01)
Hispanic vs. NH White	1.18 (0.88, 1.40)	1.15 (0.96, 1.38)	0.82 (0.64, 1.05)	0.84 (0.65, 1.08)
Hispanic vs. Asian	1.01 (0.83, 1.23)	1.00 (0.82, 1.23)	0.72 (0.49, 1.04)	0.78 (0.52, 1.16)
Asian vs. NH White	1.16 (0.93, 1.45)	1.15 (0.91, 1.44)	1.14 (0.78, 1.67)	1.07 (0.72, 1.60)

Abbreviations: RR= relative risk (adjusted for maternal age, pre-pregnancy body mass index (BMI), insurance, education, country of origin, parity, and smoking), SLE = systemic lupus erythematosus, RA = rheumatoid arthritis, NH = non-Hispanic