Table 5.

ORs and 95% CIs of DTC risk factors related to selected hormonal and reproductive characteristics

Variables	Cases (n = 179)	Controls (n = 173)	Crude OR1 (95% CI)	Adjusted OR2 (95% CI)
Age at menarche (unknown = 10)
≤11	53	42	1.4 (0.9 – 2.4)	1.5 (0.9 – 2.7)
12 – 14	79	95	1*	1*
≥15	43	30	1.6 (0.9 – 2.9)	1.7 (0.9 – 3.0)
Irregular cycles (unknown = 15)
No	140	140	1*	1*
Yes	33	24	1.4 (0.8 – 2.6)	1.6 (0.9 – 3.1)
Hormonal contraceptive
No	89	91	1*	1*
Yes	90	82	1.1 (0.7 – 1.7)	1.0 (0.7 – 1.6)
Gestational diabetes
No	172	168	1*	1*
Yes	7	5	1.4 (0.4 – 4.5)	1.4 (0.6 – 3.1)
Mammography
No	161	157	1*	1*
Yes	18	16	1.1 (0.5 – 2.3)	1.1 (0.5 – 2.6)
Menopausal status (unknown = 9)
Still menstruating	147	152	1*	1*
Natural	15	7	2.4 (0.8 – 7.0)	2.6 (0.8 – 8.2)
Artificial	14	8	1.8 (0.6 – 4.8)	1.4 (0.5 – 3.8)

¹Stratified for gender and age classes.

²Stratified for gender and age classes and adjusted for smoking status, ethnic group, level of education, number of pregnancies, height, and BMI.

^*Reference category.