Table 1. Baseline characteristics of subjects.
| Variables | N | e%(SE) |
|---|---|---|
| Number | 27,311 | |
| Breast cancer patients | 236 | 0.8(0.1) |
| Age (year) | ||
| 19–44 | 10,893 | 48.4(0.5) |
| 45–64 | 9,942 | 35.3(0.4) |
| 65–74 | 6,476 | 16.4(0.3) |
| Waist circumference (cm) | ||
| <80 | 15,240 | 59.8(0.4) |
| 80–90 | 5,283 | 27.9(0.4) |
| >90 | 3,688 | 12.2(0.3) |
| Survey year | ||
| 2007 | 1,450 | 5.1(0.5) |
| 2008 | 3,455 | 10.7(0.7) |
| 2009 | 3,783 | 11.1(0.7) |
| 2010 | 3,408 | 12.1(0.8) |
| 2011 | 3,381 | 12.5(0.8) |
| 2012 | 3,199 | 12.2(0.8) |
| 2013 | 3,024 | 12.3(0.8) |
| 2014 | 2,818 | 11.7(0.8) |
| 2015 | 2,793 | 12.2(0.8) |
| Monthly household income (10,000 won) | ||
| Lowest (≤120) | 6,926 | 20.4(0.4) |
| Medium-lowest (121–250) | 6,764 | 25.6(0.4) |
| Medium-highest (251–430) | 6,805 | 26.9(0.4) |
| Highest (≥431) | 6,816 | 27.0(0.5) |
| Education (year) | ||
| ≤6 | 8,751 | 24.7(0.4) |
| 7–9 | 2,841 | 10.0(0.2) |
| 10–12 | 8,568 | 35.5(0.4) |
| ≥13 | 7,151 | 29.8(0.4) |
| Marital status | ||
| Single | 2,974 | 15.6(0.4) |
| Married | 24,337 | 84.4(0.4) |
| Residential area | ||
| Urban | 21,335 | 81.4(0.9) |
| Rural | 5,976 | 18.6(0.9) |
| Current smoking | 1,734 | 7.2(0.2) |
| Alcohol intake in past month | 16,823 | 66.1(0.4) |
| Physically activea | 10,469 | 38.7(0.4) |
| Cancer examination in the prior 2 yearsb | 15,968 | 55.8(0.4) |
| Previous pregnancyc | 23,944 | 83.2(0.4) |
| Current or past use of oral contraceptive | 4,508 | 15.5(0.3) |
| Post-menopausal | 7,029 | 20.3(0.5) |
| Age at menarche (year) | ||
| ≤12 | 3,878 | 17.8(0.3) |
| 13–14 | 9,569 | 37.7(0.4) |
| 15–16 | 7,876 | 27.4(0.3) |
| ≥17 | 5,599 | 17.1(0.3) |
All values are given as number and estimated percentage (standard error).
aPhysically active was indicated as ‘yes’ when the subject walked for more than 30 min at a time and more than five times per week.
bCancer examination in the prior 2 years was indicated as ‘yes’ when the subject had undergone screening within the prior 2 years for any kind of cancer such as lung cancer, stomach cancer, and breast cancer etc.
cPrevious pregnancy was indicated as ‘yes’ when the a subject had ever been pregnant including normal pregnancy, ectopic pregnancy, still birth, spontaneous abortion, and induced abortion.