Table 1. Characteristics of the study population based on survey data (n=13,554), 2007–2012.
| Risk factors | Percentage | County range (%) |
|---|---|---|
| Age (years) | ||
| 35–49 | 50.4 | − |
| 50–64 | 37.1 | − |
| 65 or older | 12.5 | 4.4–47.8 |
| Race | ||
| African American | 20.8 | 0.0–75.9 |
| White | 79.2 | − |
| Education | ||
| Less than high school | 3.5 | 0.0–23.6 |
| High school or GED | 21.2 | − |
| At least some college | 75.2 | − |
| Unknown | 0.1 | − |
| Age at menarche (years) | ||
| <12 | 24.0 | 16.7–40.0 |
| 12–13 | 52.3 | − |
| 14 or older | 23.7 | − |
| Body mass index at time of survey (kg/m2) | ||
| <18.5 | 1.3 | − |
| 18.5–24.9 | 28.3 | − |
| 25.0–29.9 | 29.8 | − |
| 30 or more | 39.7 | 0.0–63.2 |
| Unknown | 1.0 | − |
| Body mass index at age 18 (kg/m2) | ||
| <18.5 | 22.5 | − |
| 18.5–24.9 | 63.1 | − |
| 25.0–29.9 | 8.5 | − |
| 30 or more | 4.4 | 0.0–12.5 |
| Unknown | 1.5 | − |
| Lactation | ||
| No (no child birth, duration 0–6 months) | 76.9 | − |
| Yes (6 or more months) | 21.7 | 0.0–50.0 |
| Unknown | 1.4 | − |
| Alcohol use | ||
| 0–<10 g/day | 86.8 | − |
| 10 g/day or more | 12.4 | 0–19.5 |
| Unknown | 0.1 | − |
| Physical activity | ||
| Inactive | 6.4 | 0–18.2 |
| Insufficiently active | 14.9 | − |
| Active | 16.9 | − |
| Highly active | 61.8 | − |
| Mean 5-year predicted breast cancer risk, % (st dev) | 1.3 (1.0) | 1.0–1.9 |
| Mean lifetime predicted breast cancer risk, % (st dev) | 9.9 (5.2) | 7.5–11.9 |
GED, graduate equivalency degree.