Table 2.

Exposed Woman Years (15–49-year-olds) to COCs for 1992–97.

Formulation	EWY⋆	Mean age (years)	Cases	Rate per 10000 EWY⋆	Rate ratio (95% CI)	Percentage of total use	used by women under 25 years	used by women over 35 years
LNG 150 µg + EE 30 µg	190191	27.4	64	3.4	REFERENCE	24.3	34.5	13.1
DSG 150 µg + EE 30 µg	152524	25.8	65	4.3	1.3 (0.9,1.8)	19.5	46.6	8.7
GST 75 µg + EE 30 µg	143581	25.9	63	4.4	1.3 (0.9,1.9)	18.3	46.6	9.6
Triphasic LNG (50 75 125) + EE (30 40 30) µg	102787	28	26	2.5	0.8 (0.5,1.2)	13.1	27.4	12.6
DSG 150 µg + EE20 µg	37584	28.8	18	4.8	1.4 (0.8,2.4)	4.8	37.7	27.3
NRG 250 µg + EE 35 µg	40440	25.8	15	3.7	1.1 (0.6,2.0)	5.2	47.6	9.7
NRT 500 µg + EE 35 µg	22981	27.5	5	2.2	0.6 (0.2,1.6)	2.9	33.3	12.4
Cyproterone acetate 2 mg + EE 35 µg	25709	25.6	16	6.2	1.8 (0.9,3.2)	3.3	47.6	8.7
Triphasic NRT + EE 35 µg	16440	27.8	7	4.4	1.3 (0.5,2.8)	2.1	27.8	11.4
LNG 250 µg + EE 30 µg	14092	30.1	8	5.7	1.7 (0.7,3.5)	1.8	22.4	23.6

^⋆Total of 783 876 exposed women years to COCs. Other formulations account for 37547 EWY.