Table 1.

Demographics of SLE and ILE cohorts defined by the 1997 ACR SLE classification criteria.

	All SLE	All ILE	P*	ILE with major clinical features+	Other ILE	P*
n	3397	440		86	354
Sex
Female, n (%)	3050 (89.8)	386 (87.7)	0.213	72 (83.7)	314 (88.7)	0.280
Age, y
Average (Range)	42.0 (8–82)	46.1 (9–81)	<0.001	42.8 (11–72)	47.0 (9–81)	0.010
Race/ethnicity, n (%)
European	1518 (44.7)	241 (54.8)	<0.001	36 (41.9)	205 (57.9)	0.010
American
African American	1093 (32.2)	105 (23.9)	<0.001	27 (31.4)	78 (22.0)	0.092
Hispanic	244 (7.2)	21 (4.8)	0.076	6 (7.0)	15 (4.2)	0.269‡
Asian American	130 (3.8)	18 (4.1)	0.889	6 (7.0)	12 (3.4)	0.136‡
American Indian	104 (3.1)	12 (2.7)	0.812	2 (2.3)	10 (2.8)	1.0
Pacific Islander	5 (0.1)	1 (0.2)	0.519‡	0 (0.0)	1 (0.3)	1.0‡
Mixed	283 (8.3)	40 (9.1)	0.653	8 (9.3)	32 (9.0)	1.0
Unknown	20 (0.6)	2 (0.5)	1.0‡	1 (1.2)	1 (0.3)	0.353‡

^*Bold P-values are significant (P<0.05).

⁺Pericarditis, renal disease, neurologic disease, hemolytic anemia, or thrombocytopenia.

^‡Comparisons performed by Fisher’s test; all other categorical variables were compared by Chi-square and age by t-test.