Table 2. OR (95% CI) of breast cancer in pre-menopausal women according to the use of hormonal contraceptive treatment.

		Age adjusted	Multivariate Adjusted*	Multivariate Adjusted**
	Case/Control	OR, 95% CI	OR, 95% CI	OR, 95% CI
Never user	216/253	1.00 (reference)	1.00 (reference)	1.00 (reference)
Ever user	199/223	1.06 (0.82–1.38)	1.11 (0.82–1.49)	1.22 (0.91–1.65)
Time since last use
Never	216/253	1.00 (reference)	1.00 (reference)	1.00 (reference)
> 10 years	120/134	0.98 (0.71–1.36)	1.14 (0.81–1.61)	1.18 (0.82–1.68)
< 10 years	37/39	1.04 (0.63–2.72)	1.16 (0.69–1.95)	1.31 (0.77–2.23)
recent (***)	12/9	1.58 (0.65–3.86)	1.68 (0.67–4.21)	1.93 (0.76–4.88)
P trend		0.59	0.22	0.09
Total duration of use
Never	216/253	1.00 (reference)	1.00 (reference)	1.00 (reference)
< 10 years	149/164	1.00 (0.74–1.34)	1.15 (0.84–1.58)	1.20 (0.87–1.67)
> 10 years	22/19	1.39 (0.72–2.71)	1.53 (0.76–3.08)	1.79 (0.88–3.65)
P trend		0.36	0.12	0.05
Type of treatment
Never	216/253	1.00 (reference)	1.00 (reference)	1.00 (reference)
Oral	47/61	0.90 (0.58–1.39)	0.94 (0.59–1.49)	0.92 (0.58–1.48)
Injected or transdermal	27/23	1.54 (0.83–2.85)	1.79 (0.91–3.53)	1.92 (0.96–3.84)
Others	9/13	0.86 (0.35–2.07)	0.99 (0.39–2.54)	0.99 (0.38–2.59)
More than one treatment	40/51	0.85 (0.53–1.36)	0.94 (0.57–1.57)	1.02 (0.61–1.71)

(*) Adjusted for: age, socioeconomically status (high/medium/low), BMI (kg/m2), familial history of breast cancer in first degree relatives (yes/no), diabetes(yes/no), number of full term pregnancy, age at first full term pregnancy (years), total duration of breast feeding (months) and age at menarche (years).

(**) additional adjusted for European ancestry.

(***) We defined the recent use as the reported use of contraceptive treatment during the year prior to the date of interview.