Table 4.
Time intervalsa | Obs | Exp | Adjusted RRb (95% confidence interval) |
---|---|---|---|
All (17 338) | 1812 | 612.5 | 3.2 (3.0–3.3) |
1st mo. (1355) | 299 | 44.1 | 7.7 (6.8–8.7) |
1–11 mo. (4117) | 612 | 151.6 | 4.5 (4.1–4.9) |
1–4 y (10 615) | 811 | 369.1 | 2.3 (2.1–2.5) |
5–6 y (1251) | 90 | 47.8 | 2.0 (1.6–2.4) |
aNumber of women with breast cancer in the reference cohort in parentheses.
bAdjusted for age in 5-year age bands, time period in single calendar years and district of residence; comparing Obs/Exp in the BBD cohort (data in table) with Obs/Exp in the reference cohort (data not shown separately).