Table 3.

 Relative risk of venous thromboembolism among current users of oral contraceptives and hormone releasing intrauterine device according to certainty of diagnosis of venous thromboembolism, with non-users of hormonal contraception as reference group

Product type	Women years	Anticoagulation (confirmed)			Not recorded
		No of events*	Adjusted relative risk† (95% CI)		No of events*	Adjusted relative risk† (95% CI)	% confirmed
Non-use	4 960 730	1004	1 (reference)		808	1 (reference)	55.4
Progestogen with 50 µg ethinylestradiol:
Norethisterone	6848	7	6.24 (2.95 to 13.2)		4	5.10 (1.90 to 13.7)	63.6
Levonorgestrel	23 691	22	4.49 (2.94 to 6.85)		9	2.34 (1.21 to 4.52)	71.0
Progestogen with 30-40 µg ethinylestradiol:
Norethisterone	27 355	8	2.24 (1.12 to 4.51)		2	0.73 (0.18 to 2.91)	80.0
Levonorgestrel phasic	105 970	66	3.09 (2.41 to 3.97)		23	1.31 (0.86 to 1.98)	74.2
Levonorgestrel combined	104 251	57	2.92 (2.23 to 3.81)		21	1.30 (0.84 to 2.00)	73.1
Norgestimate	267 664	119	3.52 (2.90 to 4.27)		46	1.44 (1.07 to 1.95)	72.1
Desogestrel	170 249	168	6.61 (5.60 to 7.80)		33	1.43 (1.01 to 2.04)	83.6
Gestodene	668 355	575	6.24 (5.61 to 6.95)		163	1.92 (1.61 to 2.28)	77.9
Drospirenone	286 859	196	6.37 (5.43 to 7.47)		70	2.32 (1.80 to 2.98)	73.7
Cyproterone	120 934	88	6.35 (5.09 to7.93)		21	1.58 (1.02 to 2.44)	80.7
Progestogen with 20 µg ethinylestradiol:
Desogestrel	470 982	246	4.81 (4.15 to 5.56)		76	1.52 (1.19 to 1.94)	76.4
Gestodene	472 118	240	5.07 (4.37 to 5.88)		81	1.72 (1.36 to 2.19)	74.8
Drospirenone	23 055	16	6.95 (4.21 to 11.5)		7	2.58 (1.22 to 5.46)	69.6
Progestogen only:
Norethisterone	44 168	6	0.68 (0.30 to 1.51)		3	0.41 (0.13 to 1.28)	66.7
Desogestrel	29 187	3	0.61 (0.20 to 1.90)		3	0.63 (0.20 to 1.97)	50.0
Levonorgestrel releasing intrauterine device	155 149	26	0.72 (0.49 to 1.06)		29	0.95 (0.65 to 1.38)	47.3

*Events are venous thromboembolisms.

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