Table 1. Distribution of baseline characteristics among the study population in the EPIC cohort presented as median (range) or percent.
| All (n=20 2206) | France (n=59 981) | Italy (n=21 727) | Spain (n=14 153) | UK (n=31 943) | Netherlands (n=20 053) | Greece (n=10 133) | Germany (n=16 259) | Denmark (n=27 957) | |
|---|---|---|---|---|---|---|---|---|---|
| No. of cases | 791 | 144 | 77 | 46 | 190 | 90 | 36 | 63 | 145 |
| Age at entry (median, range) | 52.4 (45.0, 77.8) | 52.4 (45.0, 71.4) | 53.9 (45.0, 77.8) | 52.8 (45.0, 69.8) | 56.1 (45.0, 98.5) | 55.3 (45.0, 70.1) | 60.1 (45.0, 84.4) | 55.0 (45.0, 70.1) | 56.2 (50.1, 65.8) |
|
Menopause status (%) | |||||||||
| Post | 61.5 | 49.4 | 59.8 | 56.3 | 66.3 | 64.3 | 78.3 | 64.1 | 76.3 |
| Pre/peri/unknown | 38.5 | 50.6 | 40.2 | 43.7 | 33.7 | 35.7 | 21.7 | 35.9 | 23.7 |
| Age at menopause (median, range)a | 50 (12, 67) | 50 (17, 67) | 50 (15, 62) | 50 (25, 61) | 50 (12, 67) | 50 (16, 64) | 49 (23, 66) | 50 (45, 61) | 50 (13, 64) |
| % Missing | 22.6 | 45.7 | 6.2 | 4.3 | 27.5 | 9.6 | 4.5 | 19.2 | 18.9 |
|
HRT use (%) | |||||||||
| Never | 66.9 | 66.1 | 79.3 | 85.9 | 64.4 | 75.2 | 94.1 | 33.1 | 55.8 |
| Ever | 29.8 | 33.2 | 19.1 | 11.7 | 31.2 | 23.2 | 5.3 | 47.0 | 42.4 |
| Missing | 3.3 | 0.7 | 1.6 | 2.4 | 4.4 | 1.6 | 0.6 | 19.9 | 1.8 |
| Duration of HRT use (years)b | 2.2 (0.1, 38) | 2.2 (0.1, 30) | 1.0 (0.5, 20) | 1.0 (0.5, 20) | 2.2 (0.1, 38) | 2.0 (0.5, 30) | 0.8 (0.1, 18) | 4.0 (0.5, 20) | 4.0 (0.5, 20) |
| % Missing | 3.1 | 0.02 | 6.6 | 2.1 | 7.3 | 7.1 | 1.9 | 4.8 | 6.0 |
|
Use of OCs (%) | |||||||||
| Never | 46.9 | 41.0 | 65.6 | 71.0 | 45.1 | 32.0 | 94.1 | 25.9 | 40.8 |
| Ever | 51.9 | 58.8 | 33.0 | 28.9 | 50.3 | 67.3 | 5.4 | 73.9 | 58.1 |
| Missing | 1.2 | 0.2 | 1.4 | 0.1 | 4.6 | 0.7 | 0.5 | 0.2 | 1.1 |
| Duration of OC use (years)c (median, range) | 5 (1, 25) | 5 (1, 25) | 2 (1, 25) | 2 (1, 25) | 5 (1, 25) | 8 (1, 25) | 1 (1, 25) | 10 (1, 25) | 6 (1, 25) |
| % Missing | 12.7 | 27.4 | 3.2 | 1.0 | 11.4 | 3.9 | 3.7 | 0.7 | 5.6 |
|
FTP (%) | |||||||||
| 0 | 11.0 | 8.8 | 11.8 | 9.9 | 13.8 | 12.6 | 8.4 | 12.8 | 11.4 |
| ⩾1 | 83.6 | 83.4 | 87.0 | 89.2 | 82.1 | 65.8 | 91.0 | 87.0 | 88.3 |
| Missing | 5.4 | 7.8 | 1.2 | 0.9 | 4.1 | 21.6 | 0.6 | 0.2 | 0.3 |
| Age at first FTP (median, range)d: | 25 (12, 56) | 24 (15, 48) | 25 (13, 48) | 25 (13, 48) | 25 (12, 56) | 25 (12, 45) | 24 (14, 49) | 23 (15, 44) | 23 (14, 55) |
| % Missing | 0.4 | 0.3 | 0.1 | 0.1 | 0.4 | 0.05 | 1.2 | 0.1 | 1.1 |
| Duration of breast-feeding (months) (median, range)d: | 4 (0, 286) | 2.5(0,99) | 6 (0, 84) | 9(0, 144) | 3.7 (0, 200) | 2.8 (0, 107) | 12 (0, 286) | 2 (0, 84) | 6 (0, 150) |
| % Missing | 3.2 | 5.8 | 0.2 | 0.3 | 6.5 | 0.6 | 1.2 | 0.6 | 2.1 |
|
Multiple miscarriages (%) | |||||||||
| No | 79.7 | 79.9 | 83.6 | 82.1 | 76.4 | 61.5 | 85.4 | 58.0 | 86.5 |
| Yes | 5.2 | 4.9 | 5.5 | 7.8 | 4.6 | 4.7 | 8.0 | 4.8 | 4.9 |
| Missing | 10.1 | 15.2 | 10.9 | 10.1 | 19.0 | 33.8 | 6.6 | 10.2 | 8.6 |
| Age at menarche (median, range) | 13 (8, 20) | 13 (8, 20) | 13 (8, 20) | 13 (8, 20) | 13 (8, 20) | 13 (8, 20) | 13 (8, 20) | 13 (8, 20) | 14 (8, 20) |
|
Use of intrauterine device (%) | |||||||||
| Never | 70.8 | 60.0 | 84.3 | 90.4 | 72.9 | 65.3 | 97.3 | 70.1 | 65.7 |
| Ever | 25.3 | 39.9 | 14.3 | 8.7 | 22.1 | 9.2 | 2.1 | 27.1 | 33.6 |
| Missing | 3.9 | 0.1 | 1.4 | 0.9 | 5.0 | 25.5 | 0.6 | 2.8 | 0.7 |
|
Hysterectomy (%) | |||||||||
| No | 87.0 | 88.7 | 91.7 | 95.6 | 80.4 | 79.5 | 95.6 | 81.8 | 88.4 |
| Yes | 11.2 | 8.2 | 6.8 | 4.3 | 15.5 | 19.9 | 3.9 | 18.2 | 11.4 |
| Missing | 1.8 | 3.1 | 1.5 | 0.1 | 4.1 | 0.6 | 0.5 | 0.0 | 0.2 |
|
Unilateral ovariectomy (%) | |||||||||
| No | 92.1 | 91.4 | 93.6 | 96.6 | 89.0 | 90.0 | 97.0 | 93.2 | 92.9 |
| Yes | 4.7 | 3.6 | 4.7 | 3.2 | 4.5 | 7.0 | 1.9 | 6.7 | 6.0 |
| Missing | 3.2 | 5.0 | 1.7 | 0.2 | 6.5 | 3.0 | 1.1 | 0.1 | 1.1 |
| BMI (median, range) | 24.5 (13.0, 74.5) | 22.6 (13.2, 57.9) | 25.5 (15.0, 69.4) | 28.6 (17.1, 62.2) | 24.5 (13.4, 74.5) | 24.9 (13.1, 52.8) | 29.1 (15.4, 67.1) | 25.6 (13.0, 58.7) | 24.8 (13.4, 58.6) |
|
Smoking status (%) | |||||||||
| Never | 60.1 | 67.2 | 56.6 | 85.0 | 55.7 | 41.4 | 83.2 | 62.2 | 43.9 |
| Former | 21.7 | 18.7 | 18.5 | 5.8 | 31.2 | 33.3 | 4.3 | 23.3 | 24.6 |
| Current | 15.6 | 8.5 | 23.6 | 9.2 | 9.7 | 24.7 | 9.1 | 14.3 | 31.3 |
| Missing | 2.6 | 5.6 | 1.3 | 0.0 | 3.4 | 0.6 | 3.4 | 0.2 | 0.2 |
| Alcohol intake (g per day; median, range) | 4 (0, 382) | 6 (0, 382) | 2 (0, 133) | 0 (0, 115) | 3 (0, 100) | 4 (0, 164) | 0.6 (0, 180) | 5 (0, 263) | 9 (0, 195) |
| % Missing | 1.4 | 0 | 1.3 | 0 | 7.4 | 0.5 | 0 | 0 | 0.1 |
|
Family history of breast cancer (%) | |||||||||
| No | 42.9 | 77.0 | 0 | 93.9 | 40.3 | 71.6 | 0 | 0 | 0 |
| Yes | 4.1 | 7.5 | 0 | 4.8 | 2.7 | 11.5 | 0 | 0 | 0 |
| Missing | 53.0 | 15.5 | 100 | 1.3 | 57.0 | 16.9 | 100 | 100 | 100 |
|
Pre-existing diabetes (%) | |||||||||
| No | 94.9 | 97.8 | 96.2 | 93.7 | 89.5 | 96.7 | 90.4 | 95.9 | 94.4 |
| Yes | 2.8 | 2.1 | 2.4 | 6.1 | 1.6 | 2.6 | 8.9 | 4.0 | 1.5 |
| Missing | 2.3 | 0.1 | 1.4 | 0.2 | 8.9 | 0.7 | 0.7 | 0.1 | 4.1 |
Abbreviations: BMI=body mass index; EPIC=European Prospective Investigation into Cancer and Nutrition; FTP=full-term pregnancy; HRT=hormone replacement therapy; OC=oral contraceptive.
a
Among postmenopausal women.
b
Among ever HRT users.
c
Among ever OC users.
d
Among parous women.