Table 1.

Description of the 11 OCAC studies included in the analysis.

				Cases				Controls
OCAC Study Abbreviation	Study Location	Recruitment Period	Data Collection Method	N	% with hysterectomy	% with endometriosis	%with ET or EPT Use	N	% with hysterectomy	% with endometriosis	%with ET or EPT Use
AUS	Australia	2002 – 2005	Self-completed questionnaire	512	17.0	6.6	HT data n/a	454	21.8	4.2	HT data n/a
GER	Baden-Württemberg And Rhineland-Palatinate	1993 – 1998	Self-completed questionnaire	147	29.3	1.4	21.8	323	35.0	1.6	28.5
MAL	Denmark	1994 – 1999	In-person or phone interview	311	14.2	1	40.8	814	10.4	0.7	38
CON	Connecticut, USA	1999 – 2003	In-person interview	240	25.0	7.5	40	270	18.5	8.5	45.9
DOV	Washington, USA	2002 – 2009	In-person interview	669	27.1	10.5	59.5	1058	21.6	6.6	63.3
HAW	Hawai’i, USA	1993 – 2008	In-person interview	433	18.5	9	45.7	582	15.6	6.2	53.1
HOP	Western Pennsylvania, Northeast Ohio, Western New York, USA	2003 – 2009	In-person interview	456	27.0	6.6	41.9	1021	21.3	6.6	45.6
NCO	North Carolina, USA	1999 – 2008	In-person interview	286	21.0	8.7	HT data n/a	311	17.4	3.2	HT data n/a
NEC	New Hampshire and Eastern Massachussets, USA	1992 – 2008	In-person interview	847	13.2	9.2	29.4	1048	14.6	8.3	33.6
UCI	Orange County and San Diego County, CA	1996 – 2005	Self-completed questionnaire	211	37.0	13.7	70.6	296	40.5	14.2	73.3
USC	Los Angeles, California	1994 – 2010	In-person interview	1238	23.3	8.3	45.5	1367	18.3	6.4	49.3
All Studies				5350	21.6	8.1	44.0	7544	19.4	6.0	47.4