Table 3.
Relative risk of ovarian cancer in former users of hormonal contraception by time since last current use and duration of use
| Duration of use | Time since last current use of hormonal contraception | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1-<5 years | 5-<10 years | ≥10 years | |||||||||
| No of person years | No of ovarian cancer events | Relative risk (95% CI)* | No of person years | No of ovarian cancer events | Relative risk (95% CI)* | No of person years | No of ovarian cancer events | Relative risk (95% CI)* | |||
| ≤1 year | 667 835 | 37 | 0.81 (0.58 to 1.13) | 470 243 | 45 | 1.14 (0.84 to 1.56) | 316 850 | 27 | 0.81 (0.54 to 1.21) | ||
| >1-≤5 years | 1 038 886 | 47 | 0.84 (0.62 to 1.15) | 635 891 | 29 | 0.66 (0.45 to 0.98) | 308 126 | 22 | 0.76 (0.48 to 1.20) | ||
| >5 years | 735 899 | 26 | 0.60 (0.39 to 0.91) | 291 123 | 9 | 0.41 (0.21 to 0.81) | 40 304 | 2 | 0.57 (0.14 to 2.33) | ||
*
Adjusted for calendar year, parity, age, education, tubal sterilisation, hysterectomy, endometriosis, polycystic ovary syndrome, and family history of breast or ovarian cancer.