Use of oral contraceptives in Denmark 1980-1990 and smoking habits among fertile women in 1990
Lidegaard, O.
Ugeskrift for Laeger 155(44): 3550-3558
1993
ISSN/ISBN: 0041-5782 PMID: 8236576 Document Number: 333675
The objective was to outline the changes in usage of different types of oral contraceptives (OCs) during 1980-90 as well to estimate to what extent these changes can be expected to influence the incidence of cerebral thromboembolic attacks among fertile women, the use of different types of OCs and smoking habits in different age groups were also investigated. Data were derived from cross-sectional studies during the period 1980-1990; and data on the use of the pill was obtained from national sales statistics from 1980-1990 as well as from questionnaires answered by 1370 healthy women in 1990. The control group was an age-matched group of women with cerebral thrombosis in the age range of 15-44. The total sale of the pill was fairly stable throughout the decade, corresponding to a theoretical user percentage of 23-26. The proportion of pills sold containing 50 mcg estrogen had fallen steadily from 51% in 1980 to 11% in 1990; the proportion of pills containing 30-40 mcg estrogen (including the multi-phase pills) had doubled from almost 40% to nearly 80% over the same period; while the proportion of minipills had fallen from 10% to 5%. Among 15-24, 25-34, and 35-44 year old women, 50%, 20%, and 8%, respectively, used OCs in 1990. Use of low-dose pills (30-40 mcg estrogen) was 87% among women aged 15-24 (p 0.001), while almost 25% of the older women still used medium-dose pills (50 mcg estrogen) and another 25% used minipills. Among women aged 15-24, 40% used OCs who had 7-9 years of schooling vs. 67% of those with 10-12 years and 35% of those with more than 12 years of education. The women's level of education was only weakly associated with OC use. Among 15-24, 25-34 and 35-44 year old women, 34.5%, 53.0%, and 48.8%, respectively, smoked cigarettes in 1990. 50% more smokers were found among women with 7-9 years of schooling than among women with 10-12 or more than 12 years of education. There was no difference in the percentage of smokers among women using the pill (47%) and women not using OCs (49%).