Table 1.

Demographic characteristics of women without autoimmune disease and rate per 1000^a (and frequency) of autoimmune disease by demographic variables from the Consortium of Safe Labor, 2002–2008 (n = 205521).

	Women without autoimmune disease (N = 204384)	Autoimmune Disease Rate of disease per 1000 (n)
		Type I Diabetes 2.4 (507)	Systemic Lupus Erythematosus 0.9 (202)	Crohn’s Disease 0.8 (169)	Multiple Sclerosis 0.7 (146)	Rheumatoid Arthritis 0.5 (123)
Race
White	514.4 (105136)	2.6 (280)	0.9 (99)	1.4 (144)	1.0 (104)	0.8 (81)
Black	208.3 (42576)	2.9 (124)	1.3 (57)	0.5 (20)	0.7 (28)	0.5 (20)
Hispanic	168.5 (34439)	2.0 (70)	0.9 (30)	< 0.1 (1)	0.2 (8)	0.3 (10)
Other	108.7 (22233)	0.1 (33)	< .01 (16)	< 0.1 (4)	< 0.1 (6)	< 0.1 (12)
	p < 0.01	p < 0.01	p = 0.16	p < 0.01	p < 0.01	p = 0.02
Age
< 20	92.7 (18953)	2.5 (47)	0.3 (6)	0.5 (9)	0.1 (2)	0.6 (12)
20-24	253.6 (51829)	2.4 (127)	0.9 (49)	0.5 (25)	0.3 (15)	0.3 (14)
25-29	280.4 (57304	2.4 (136)	0.9 (52)	1.0 (56)	0.6 (34)	0.4 (22)
30-34	224.2 (45826	2.6 (121)	1.4 (64)	1.1 (52)	1.2 (55)	0.8 (36)
> =35	149.1 (30472)	2.5 (76)	1.0 (31)	0.9 (27)	1.3 (40)	1.3 (39)
	p < 0.01	p = 0.70	p < 0.01	p < 0.01	p < 0.01	p < 0.01
Insurance
Private	571.6 (116823)	2.5 (299)	1.1 (135)	1.1 (127)	0.9 (102)	0.7 (79)
Public	303.3 (61982)	2.9 (181)	1.0 (65)	0.5 (34)	0.5 (32)	0.6 (36)
Other	125.1 (25578)	0.9 (27)	0.1 (2)	0.3 (8)	0.5 (12)	0.3 (8)
	p < 0.01	p < 0.01	p < 0.01	p < 0.01	p = 0.02	p = 0.19
Region
Northeast	190.6 (38958)	1.7 (67)	0.7 (26)	1.4 (54)	0.8 (32)	0.7 (29)
South	388.1 (79336)	2.9 (228)	1.4 (115)	0.8 (61)	0.7 (55)	0.7 (57)
Midwest	102.3 (20919)	3.1 (65)	0.9 (18)	0.9 (18)	0.7 (15)	0.4 (9)
West	318.8 (65171)	2.2 (147)	0.7 (43)	0.5 (36)	0.7 (44)	1.4 (28)
	p < 0.01	p < 0.01	p < 0.01	p < 0.01	p = 0.84	p = 0.06

p-values assessed using fisher’s exact test.

^aRates per 1000 are specific for each demographic category (rate = (outcome n/autoimmune disease N)*1000).