Table 6

 Relative risk of venous thromboembolism in current users of combined oral contraceptives according to length of use and with non-users of hormonal contraception as reference

Product typeWomen yearsNo of events*Adjusted relative risk† (95% CI)
<3 months3-12 months>1-4 years>4 years
Non-use4 960 73018121 (reference)1 (reference)1 (reference)1 (reference)
Progestogen with 30-40 μg ethinylestradiol:
 Levonorgestel (all)210 2211674.07 (2.70 to 6.15)2.54 (1.80 to 3.59)2.12 (1.61 to 2.80)1.88 (1.45 to 2.43)
 Norgestimate267 6641653.81 (2.60 to 5.58)2.98 (2.22 to 4.00)2.47 (1.91 to 3.20)1.82 (1.27 to 2.59)
 Desogestrel170 2492014.59 (3.01 to 7.00)4.20 (3.11 to 5.67)3.77 (2.95 to 4.81)4.64 (3.64 to 5.92)
 Gestodene668 3557384.83 (3.85 to 6.05)4.65 (3.96 to 5.45)4.12 (3.61 to 4.70)3.94 (3.43 to 4.54)
 Drospirenone286 8592664.70 (3.45 to 6.40)5.95 (4.88 to 7.24)3.38 (2.69 to 4.24)4.34 (3.10 to 6.08)
 Cyproterone120 9341094.23 (2.50 to 7.17)4.21 (2.95 to 6.01)4.90 (3.70 to 6.49)2.43 (1.41 to 4.19)
Progestogen with 20 μg ethinylestradiol:
 Desogestrel470 9823223.18 (2.31 to 4.38)3.18 (2.55 to 3.98)3.49 (2.91 to 4.17)3.09 (2.42 to 3.96)
 Gestodene472 1183213.46 (2.49 to 4.81)4.51 (3.69 to 5.52)3.38 (2.81 to 4.06)2.65 (2.00 to 3.51)
 Drospirenone23 055236.16 (2.76 to 13.77)7.25 (4.19 to 12.56)2.58 (0.96 to 6.89)

*Events are venous thromboembolisms.

†Adjusted for age, calendar year, and level of education.