Table 5

 Rate ratio of confirmed venous thromboembolism between different combined oral contraceptives with adjustment for length of use

Product groupWomen yearsNo of events*Adjusted rate ratio† (95% CI)P value
Progestogen with 30-40 μg ethinylestradiol:
 Norethisterone27 35580.76 (0.36 to 1.60)0.47
 Levonorgestrel phasic105 970661.07 (0.75 to 1.52)0.71
 Levonorgestrel combined104 251571 (reference)
 Norgestimate267 6641191.18 (0.86 to 1.62)0.30
 Desogestrel170 2491682.24 (1.65 to 3.02)<0.001
 Gestodene668 3555752.12 (1.61 to 2.78)<0.001
 Drospirenone286 8591962.09 (1.55 to 2.82)<0.001
 Cyproterone120 934882.11 (1.51 to 2.95)<0.001
Progestogen with 20 μg ethinylestradiol:
 Desogestrel470 9822461.60 (1.20 to 2.14)0.0015
 Gestodene472 1182401.70 (1.27 to 2.27)0.0004
 Drospirenone23 055162.22 (1.27 to 3.89)0.005

*Events are venous thromboembolisms.

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