Table 1 Demographic, medical history, and reproductive characteristics of breast cancer cases and controls

< 50

28 (24)

43 (37)

0.6 (0.3–1.4)

50–54

43 (37)

33 (28)

1.3 (0.6–2.0)

55–59

25 (22)

24 (21)

1 (ref.)

60 ≥

20 (17)

16 (14)

1.2 (0.5–2.9)

1.0 (0.3)

Mean (SD)

54.6 (6.8)

52.7 (6.8)

0.03*

Marital status

never married

7 (6)

4 (4)

1.0 (ref.)

married

86 (74)

84 (72)

0.7 (0.2–2.5)

widowed/divorced

23 (20)

28 (24)

0.6 (0.1–2.3)

0.7 (0.4)

Educational status

illiterate

22 (19)

29 (25)

1.0 (ref.)

primary education

36 (31)

31 (27)

1.5 (0.7–3.3)

secondary education

38 (33)

42 (36)

1.2 (0.6–2.6)

higher education

20 (17)

14 (12)

1.9 (0.7–4.8)

0.9 (0.4)

Family history of breast cancer

none

88 (76)

94 (81)

1.0 (ref.)

first or second degree

28 (24)

22 (19)

1.4 (0.2–9.7)

0.7 (0.4)

Age at menarche (years)

< 13

28 (24)

18 (16)

1.0 (ref.)

13

36 (32)

33 (28)

0.8 (0.3–1.7)

14

26 (22)

37 (32)

0.5 (0.2–1.1)

14 >

26 (22)

28 (24)

0.6 (0.3–1.4)

2.2 (0.1)

Parity

nulliparous

11 (9)

7 (6)

1.0 (ref.)

multiparous

105 (91)

109 (94)

0.7 (0.2–1.9)

0.7 (0.4)

Age at first live birth (years)

14–19

36 (34)

46 (42)

1.0 (ref.)

20–24

44 (42)

43 (40)

1.3 (0.7–2.4)

25–29

17 (16)

13 (12)

1.7 (0.7–4.0)

30 ≥

8 (8)

7 (6)

1.7 (0.5–5.2)

1.6 (0.2)

Number of live births

none

11 (9)

7 (6)

1.0 (ref.)

1–2

27 (24)

33 (28)

0.6 (0.2–1.8)

3–4

45 (39)

32 (28)

0.9 (0.3–2.9)

> 4

33 (28)

44 (38)

0.5 (0.2–1.5)

0.8 (0.4)

Age at menopause (years)

< 45

29 (25)

40 (35)

1.0 (ref.)

45–50

59 (51)

53 (45)

1.6 (0.8–3.0)

> 50

28 (24)

23 (20)

1.7 (0.8–3.7)

1.9 (0.2)

Previous use of oral contraceptives

none

73 (63)

75 (65)

1.0 (ref.)

yes

43 (37)

41 (35)

1.1 (0.6–2.0)

0.1 (0.8)