Table 1 Age-adjusted characteristics of n = 112,639 NHSII women over follow-up from 1989 to 2013 by cumulative average radon quintile
From: Environmental radon exposure and breast cancer risk in the Nurses’ Health Study II
Overall | Radon quintile 1 (<27.0 Bq/m3) | Radon quintile 2 (≥27.0–37.7 Bq/m3) | Radon quintile 3 (≥37.7–50.1 Bq/m3) | Radon quintile 4 (≥50.1–74.9 Bq/m3) | Radon quintile 5 (≥74.9 Bq/m3) | |
|---|---|---|---|---|---|---|
Person-years (n) | 2,502,695 | 496,494 | 503,957 | 503,121 | 499,349 | 499,773 |
Cumulative average radon (Bq/m3) (mean ± SD) | 54.7 ± 38.5 | 19.2 ± 3.9 | 32.2 ± 3.1 | 43.3 ± 3.5 | 61.5 ± 6.6 | 117.3 ± 38.5 |
Age (years) (mean ± SD) | 45.4 ± 8.3 | 45.8 ± 8.2 | 45.3 ± 8.3 | 45.2 ± 8.3 | 45.4 ± 8.2 | 45.4 ± 8.3 |
White (%) | 96 | 91 | 94 | 96 | 98 | 98 |
Family history of breast cancer (%) | 11 | 11 | 11 | 11 | 11 | 10 |
Personal history of biopsy-confirmed benign breast disease (BBD) (%) | 17 | 17 | 17 | 18 | 17 | 17 |
Menopausal status and hormone use (%) | ||||||
Premenopausal | 67 | 67 | 67 | 68 | 67 | 67 |
Never users | 5 | 4 | 5 | 5 | 5 | 5 |
Past users | 11 | 11 | 11 | 11 | 11 | 11 |
Current users | 8 | 9 | 8 | 7 | 7 | 8 |
Missing | 9 | 10 | 10 | 9 | 9 | 9 |
Age at menarche (years) (mean ± SD) | 12.4 ± 1.4 | 12.4 ± 1.5 | 12.4 ± 1.5 | 12.4 ± 1.4 | 12.4 ± 1.4 | 12.4 ± 1.4 |
Parity and age at first birth (%) | ||||||
Nulliparous | 17 | 21 | 18 | 17 | 16 | 14 |
1–2 children <25 | 14 | 13 | 13 | 13 | 15 | 16 |
1–2 children ≥25–30 | 19 | 18 | 19 | 19 | 20 | 21 |
1–2 children ≥30 | 13 | 15 | 13 | 13 | 12 | 11 |
3+ children <25 | 11 | 8 | 10 | 12 | 12 | 14 |
3+ children ≥25–30 | 10 | 8 | 9 | 11 | 11 | 11 |
3+ children ≥30 | 2 | 2 | 3 | 3 | 2 | 2 |
Missing | 13 | 15 | 14 | 13 | 12 | 11 |
Breastfeeding (%) | ||||||
Never | 13 | 9 | 13 | 14 | 14 | 14 |
Ever | 55 | 53 | 54 | 55 | 55 | 58 |
Missing | 11 | 12 | 12 | 11 | 11 | 11 |
Oral contraceptive (OC) use (%) | ||||||
Never | 12 | 10 | 12 | 13 | 13 | 11 |
Past | 73 | 73 | 72 | 71 | 73 | 76 |
Current | 7 | 7 | 7 | 6 | 6 | 6 |
Missing | 9 | 10 | 10 | 9 | 8 | 7 |
Screening mammogram (%) | ||||||
No mammogram | 22 | 22 | 22 | 22 | 22 | 22 |
Screening mammogram | 52 | 51 | 51 | 53 | 52 | 53 |
Missing | 26 | 28 | 27 | 26 | 26 | 25 |
Height (in) (mean ± SD) | 64.9 ± 2.6 | 64.8 ± 2.7 | 64.8 ± 2.6 | 64.9 ± 2.6 | 64.8 ± 2.6 | 64.9 ± 2.6 |
Body mass index (BMI) (kg/m2) at age 18 (mean ± SD) | 21.2 ± 3.2 | 21.0 ± 3.0 | 21.2 ± 3.1 | 21.3 ± 3.2 | 21.3 ± 3.2 | 21.4 ± 3.2 |
Current BMI (kg/m2) (mean ± SD) | 25.5 ± 4.9 | 25.1 ± 4.8 | 25.4 ± 4.9 | 25.5 ± 4.9 | 25.6 ± 4.9 | 25.8 ± 5.0 |
Smoking status (%) | ||||||
Never | 65 | 66 | 64 | 63 | 63 | 68 |
Past | 25 | 25 | 26 | 26 | 25 | 22 |
Current | 9 | 8 | 9 | 9 | 10 | 9 |
Alternate Healthy Eating Index (AHEI) (mean ± SD) | 53.5 ± 9.8 | 55.3 ± 9.7 | 54.0 ± 9.7 | 53.4 ± 9.8 | 52.8 ± 9.7 | 52.0 ± 9.8 |
Cumulative average adult alcohol consumption (g/day) (mean ± SD) | 3.2 ± 5.2 | 3.6 ± 5.9 | 3.3 ± 5.2 | 3.2 ± 5.1 | 3.0 ± 4.9 | 2.7 ± 4.8 |
Alcohol consumption at age 15 (g/day) (mean ± SD) | 1.1 ± 3.6 | 1.1 ± 3.7 | 1.1 ± 3.6 | 1.2 ± 3.9 | 1.0 ± 3.5 | 0.9 ± 3.4 |
Alcohol consumption at age 18 (g/day) (mean ± SD) | 5.1 ± 8.2 | 4.6 ± 7.8 | 5.0 ± 8.0 | 5.6 ± 8.5 | 5.4 ± 8.4 | 4.9 ± 8.0 |
Physical activity (MET hours/week) (mean ± SD) | 19.8 ± 27.9 | 20.1 ± 28.4 | 19.8 ± 28.4 | 20.2 ± 28.7 | 19.7 ± 27.5 | 19.1 ± 26.4 |
Census tract median home value ($10,000) (mean ± SD) | 16.3 ± 12.1 | 22.2 ± 16.2 | 18.2 ± 13.0 | 15.9 ± 11.7 | 13.3 ± 8.5 | 12.0 ± 5.3 |
Census tract median income ($) (mean ± SD) | 63,669 ± 23,805 | 67,010 ± 26,620 | 66,984 ± 25,438 | 65,599 ± 24,124 | 60,849 ± 22,655 | 57,871 ± 17,755 |
Individual-level income >$100,000 (%) | 21 | 25 | 23 | 22 | 19 | 18 |
Married (%) | 56 | 52 | 55 | 56 | 57 | 60 |
Living alone (%) | 7 | 8 | 7 | 7 | 7 | 6 |
Region of residence (%) | ||||||
Northeast | 33 | 9 | 27 | 43 | 54 | 32 |
Midwest | 32 | 1 | 30 | 41 | 30 | 59 |
West | 15 | 51 | 15 | 5 | 3 | 2 |
South | 19 | 38 | 29 | 11 | 12 | 7 |
Cumulative average PM2.5 (10 μg/m3) (mean ± SD) | 1.5 ± 0.3 | 1.5 ± 0.4 | 1.5 ± 0.3 | 1.5 ± 0.3 | 1.6 ± 0.3 | 1.5 ± 0.3 |
Cumulative average PM2.5–10 (10 μg/m3) (mean ± SD) | 1.1 ± 0.5 | 1.4 ± 0.6 | 1.1 ± 0.5 | 0.9 ± 0.4 | 0.9 ± 0.3 | 1.0 ± 0.4 |
Population density (per mi2) (mean ± SD) | 3779 ± 10,885 | 3872 ± 5032 | 4432 ± 8188 | 6546 ± 20,144 | 2486 ± 8479 | 1533 ± 2252 |
Urbanicity (%) | ||||||
Urban | 84 | 88 | 88 | 88 | 82 | 71 |
Urban Cluster | 9 | 7 | 6 | 7 | 10 | 16 |
Small Town Rural | 7 | 5 | 5 | 5 | 8 | 13 |
Percent of county occupied housing units: built after 1990 (mean ± SD) | 23.1 ± 12.3 | 26.3 ± 13.4 | 23.4 ± 14.0 | 21.0 ± 11.7 | 20.6 ± 10.5 | 24.3 ± 10.3 |
Percent of county occupied housing units: single-unit detached/attached (mean ± SD) | 71.4 ± 11.4 | 66.8 ± 8.5 | 70.6 ± 11.0 | 70.4 ± 16.8 | 73.3 ± 8.9 | 76.1 ± 6.8 |
Ever-moved (%) | 79 | 83 | 81 | 79 | 75 | 76 |