Decline in cerebral thromboembolism among young women after introduction of low-dose oral contraceptives: an incidence study for the period 1980-1993.
The aim of this study was to analyze age-specific incidence rates (IRs) of cerebral thromboembolic attacks (CTA) among women and men 15-44 years of age in Denmark from 1980 through 1993 and to quantify possible influences from oral contraceptives (OC) on the incidence figures. The discharge diagnoses ICD 432-436 from all Danish neurological, neurosurgical and medical departments during the period 1980-1993 were identified in a central diagnosis register. The use of OC was achieved from complete sale statistics during the study period and cross-sectional studies assessing the type-specific use of OC at different ages. During the 14-year study period, 2,100 female and 2,552 male attacks were registered. Men had an exponentially increasing IR with increasing age. Compared with men in the period 1980-86, women had more attacks in the 20-35-year age group and fewer attacks above the age of 35. After 1987 the sex differences below the age of 35 were not significant. From the first half (1980-86) to the last half (1987-1993) of the study period, women below 30 years had a significantly falling CTA IR of -20.4%, compared with a non-significant fall of -9.5% among men below 30 years. In the age group above 30 years, women experienced a not significant increase of 4.2%, men a significant increase of 11.4%. Assuming that use of OC implied an average relative risk of CTA 111115 and pregnancy a relative risk of 4, a correction was made for the contribution of incident cases among women. (ABSTRACT TRUNCATED AT 250 WORDS)
Lidegaard
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Department of Obstetrics and Gynaecology, Herlev Hospital, University of Copenhagen, Denmark.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D003276:Contraceptives, Oral / Q000009:adverse effects*; D003718:Denmark / Q000453:epidemiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D015994:Incidence; D002542:Intracranial Embolism and Thrombosis / Q000453:epidemiology* / Q000209:etiology*; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D013997:Time Factors
D003276:Contraceptives, Oral