From: Age at first childbirth and breast cancer survival: a prospective cohort study
Factor | Number of cases | Unadjusted HR | Number of cases | Adjusted HRa | Number of cases | Adjusted HRb |
---|---|---|---|---|---|---|
Age at first birth | 765 | – | 685 | – | 382 | – |
Nullipara | 83 | 1.33 (0.69–2.53) | 82 | 1.58 (0.51–4.89) | 50 | 1.42 (0.16–12.26) |
< 20 | 114 | 1.00 | 113 | 1.00 | 72 | 1.00 |
21 to ≤ 25 | 252 | 0.76 (0.43–1.33) | 240 | 0.64 (0.35–1.15) | 120 | 0.58 (0.26–1.32) |
26 to ≤ 30 | 188 | 0.70 (0.38–1.28) | 179 | 0.67 (0.35–1.27) | 96 | 0.88 (0.38–2.02) |
> 30 | 74 | 0.69 (0.31–1.53) | 71 | 0.80 (0.33–1.90) | 36 | 0.59 (0.19–1.81) |
Missing | 54 | 1.27 (0.60–2.68) | 18 | 1.43 (0.34–5.97) | 8 | 0.49 (0.34–7.38) |