Table 2.
Median, crude mean and adjusted mean percentage and absolute mammographic density by smoking status
| Smoking status | n | Percentage mammographic density (%) | Absolute mammographic density (cm2) | ||||
| Median (range) | Crude mean (95% confidence interval) | Adjusted mean (95% confidence interval) | Median (range) | Crude mean (95% confidence interval) | Adjusted mean (95% confidence interval) | ||
| Current smokers | 310 | 9.4 (0–59.4) | 8.0 (7.0–9.1) | 7.3 (6.5–8.3) | 13.7 (0–110.1) | 10.7 (9.4–12.2) | 10.4 (9.0–12.0) |
| Former smokers | 279 | 7.7 (0–51.1) | 6.7 (5.8–7.7) | 7.5 (6.6–8.5) | 11.9 (0–155.2) | 9.7 (8.4–11.4) | 10.6 (9.2–12.2) |
| Never smokers | 318 | 11.9 (0–69.2) | 9.7 (8.6–11.0) | 9.5 (8.4–10.7) | 17.1 (0–152.3) | 14.0 (12.3–15.9) | 13.7 (11.9–15.7) |
| P valuea | 0.03 | 0.003 | 0.004 | 0.005 | |||
| P valueb | <0.001 | 0.006 | <0.001 | 0.01 | |||
Analyses are adjusted for age at screening, age at first birth, number of children, age at menopause, postmenopausal hormone therapy use, and body mass index. Reported means are back-transformed from log-transformed estimated means. aCurrent smokers versus never smokers. bFormer smokers versus never smokers.