Table 2.

Comparison of mean age of SLE onset between group of SLE patients with hysterectomy performed before SLE onset and those cases with negative history of hysterectomy matched based on age of participant in three separate decades (30–39, 40–49, 50–59) for each ethnicity.

Age at study (yr)*	Mean age of SLE onset (yr)		P values
	Hysterectomy performed before SLE onset	SLE patients with negative history of Hysterectomy
European-American	N=128†	N=191†
Age 30–39	33.2 (27.89 – 38.44)	23.9 (22.18– 25.52)	1.00E-03
Age 40–49	38.8 (36.64– 41.03)	31.4 (29.60 – 33.17)	1.00E-04
Age 50–59	46.1 (44.12 – 48.09)	38.6 (36.11 – 41.02)	1.00E-04
African-American	N=52†	N=195†
Age 30–39	29.2 (23.60–34.90)	24.8 (23.45– 26.18)	1.20E-01
Age 40–49	37.2 (34.14 –40.26)	31.4 (29.61–33.17)	1.00E-03
Age 50–59	46.8 (42.75– 50.85)	37.2 (34.33 – 40.13)	3.00E-04

^*Age of subjects at the time of participation into the study.

^†Number of independent cases in the age window of 30 and 60 years old for each ethnicity.