Table 3 Association between biopsychosocial factors and level of breast cancer risk, stratified by age (n = 3060)

Biological factors

BMI

 < 30

2,339 (94.1)

541 (94.3)

0.880

1,088 (94.0)

75 (94.9)

0.722

1,251 (94.2)

466 (94.1)

0.961

 ≥ 30

147 (5.9)

33 (5.7)

70 (6.0)

4 (5.1)

77 (5.8)

29 (5.9)

Having pregnancy

 No

335 (13.5)

54 (9.4)

0.008

228 (19.7)

4 (5.1)

0.001

107 (8.1)

50 (10.1)

0.167

 Yes

2,151 (86.5)

520 (90.6)

930 (80.3)

75 (94.9)

1,221 (91.9)

445 (89.9)

Age at 1st pregnancy

 No pregnant

335 (13.5)

54 (9.4)

< 0.001

228 (19.7)

4 (5.1)

< 0.001

107 (8.1)

50 (10.1)

< 0.001

 < 20

327 (13.1)

20 (3.5)

138 (11.9)

4 (5.1)

189 (14.2)

16 (3.3)

 20–35

1,787 (71.9)

485 (84.5)

767 (66.2)

67 (84.8)

1,020 (76.8)

418 (84.4)

 > 35

37 (1.5)

15 (2.6)

25 (2.2)

4 (5.1)

12 (0.9)

11 (2.2)

Birth experience

 No

408 (16.4)

67 (11.7)

0.005

278(24.0)

4 (5.1)

< 0.001

130 (9.8)

63 (12.7)

0.070

 Yes

2,078 (83.6)

507 (88.3)

880 (76.0)

75 (94.9)

1,198 (90.2)

432 (87.3)

Breastfeeding practice

 Never

194 (7.8)

66 (11.5)

0.014

164 (14.2)

4 (5.1)

0.009

30 (2.3)

62 (12.5)

< 0.001

 No

886 (35.6)

203 (35.4)

322 (27.8)

16 (20.3)

564 (42.5)

187 (37.8)

 Yes

1,406 (56.6)

305 (53.1)

672 (58.0)

59 (74.7)

734 (55.2)

246 (49.7)

Menopause

 No

1,343 (54.0)

172 (30.0)

< 0.001

1,072 (92.6)

71 (89.9)

0.381

271 (20.4)

101 (20.4)

0.999

 Yes

1,143 (46.0)

402 (70.0)

86 (7.4)

8 (10.1)

1,057 (79.6)

394 (79.6)

Psychological and behavioral factors

Depression status

 No

2,356 (94.8)

548(95.5)

0.492

1,106 (95.5)

76 (96.2)

0.772

1,250 (94.1)

472 (95.4)

0.308

 Yes

130 (5.2)

26 (4.5)

52 (4.5)

3 (3.8)

78 (5.9)

23 (4.6)

Alcohol consumption

 Never / occasionally

2,427 (97.6)

561 (97.7)

0.091

1,129 (97.5)

77 (97.5)

0.772

1,298 (97.7)

484 (97.8)

0.065

 Not recently

17 (0.7)

0 (0.0)

6 (0.5)

0 (0.0)

11 (0.8)

0 (0.0)

 Recently

42 (1.7)

13 (2.3)

23 (2.0)

2 (2.5)

19 (1.5)

11 (2.2)

Smoking

 No

2,244 (90.3)

516 (89.9)

0.788

1,016 (87.7)

58 (86.1)

0.664

1,128 (92.5)

448 (90.5)

0.171

 Yes

242 (9.7)

58 (10.1)

142 (12.3)

11 (13.9)

100 (7.5)

47 (9.5)

Secondhand smoke

 No

2,290 (92.1)

553 (96.3)

< 0.001

1,048 (90.5)

77 (97.5)

0.037

1,242 (93.5)

476 (96.2)

0.032

 Yes

196 (7.9)

21 (3.7)

110 (9.5)

2 (2.5)

86 (6.5)

19 (3.8)

Exercise

 No

1,483 (59.7)

301 (52.4)

0.002

851 (73.5)

60 (75.9)

0.631

632 (47.6)

241 (48.7)

0.677

 Yes

1,003 (40.3)

273 (47.6)

307 (26.5)

19 (24.1)

696 (52.4)

254 (51.3)

Social factors

Marital Status

 Unmarried

300 (12.1)

44 (7.7)

0.003

220 (19.0)

5 (6.3)

0.005

80 (6.0)

39 (7.9)

0.154

 Married

2,186 (87.9)

530 (92.3)

938 (81.0)

74 (93.7)

1,248 (94.0)

456 (92.1)

Educational level

 Primary school

294 (11.8)

43 (7.5)

0.003

45 (3.9)

0 (0.0)

0.074

249 (18.8)

43 (8.7)

< 0.001

 High school or above

2,191 (88.2)

531 (92.5)

1,113 (96.1)

79 (100.0)

1,079 (81.3)

452 (91.3)

Job experience

 No

1,720 (69.2)

440 (76.7)

< 0.001

813 (70.2)

56 (70.9)

0.898

907 (68.3)

384 (77.6)

< 0.001

 Yes

766 (30.8)

134 (23.3)

345 (29.8)

23 (29.1)

421 (31.7)

111 (22.4)

Dependency

 Not live alone

2,250 (90.5)

528 (92.0)

0.269

1,083 (93.5)

77 (6.5)

0.160

1,167 (87.9)

451 (91.1)

0.052

 Live alone

236 (9.5)

46 (8.0)

75 (6.5)

2 (2.5)

161 (12.1)

44 (8.9)