Table 4 Adjusted odds ratios (OR) and 95% confidence intervals (CI) for association between breast cancer overall and subtypes of breast cancer, and the duration of estrogen and progestin therapy (EPT) by body mass index (BMI)

 Never used

6154

1056

1

Reference

6880

1402

1

Reference

  < =5

1740

316

1.20

(1.00, 1.44)

1812

420

1.13

(0.97, 1.32)

 >5

1623

495

1.96

(1.64, 2.34)

1615

456

1.31

(1.12, 1.54)

  p-trend*

<0.0001

<0.0001

  p for interaction

0.001

  Never used

3424

550

1

Reference

3892

789

1

Reference

   < =5

959

176

1.36

(1.06, 1.74)

987

243

1.22

(0.99, 1.50)

  >5

896

293

2.29

(1.80, 2.91)

906

270

1.38

(1.12, 1.71)

   p-trend

<0.0001

0.002

   p for interaction

0.001

  Never used

850

173

1

Reference

887

178

1

Reference

   < =5

257

57

1.13

(0.74, 1.71)

295

59

0.83

(0.54, 1.29)

  >5

243

71

1.22

(0.79, 1.88)

256

47

0.83

(0.51, 1.35)

   p-trend

0.34

0.37

   p for interaction

0.03

  Never used

450

81

1

Reference

544

113

1

Reference

   < =5

137

16

0.85

(0.40, 1.81)

144

29

0.82

(0.45, 1.49)

  >5

127

28

1.56

(0.67, 3.60)

130

43

1.56

(0.87, 2.78)

   p-trend

0.44

0.24

   p for interaction

0.52

  Never used

269

54

1

Reference

296

56

1

Reference

   < =5

80

16

1.14

(0.44, 2.95)

77

14

1.38

(0.62, 3.08)

  >5

49

13

1.53

(0.57, 4.05)

57

17

1.28

(0.56, 2.93)

   p-trend

0.41

0.43

   p for interaction

0.89

  Never used

457

94

1

Reference

522

101

1

Reference

   < =5

123

20

0.96

(0.45, 2.04)

110

34

1.40

(0.79, 2.47)

  >5

113

25

1.27

(0.56, 2.86)

100

27

1.34

(0.71, 2.54)

   p-trend

0.63

0.25

   p for interaction

0.09