The population-based group of control women was identified by random digit dialing and matched according to age, area of residence, and year of event. All cases were included from 1995 to 1998. Ischaemic stroke of cardioembolic origin was excluded by the presence of atrial fibrillation or suggestive cardiac ultrasound imaging. Clinical symptoms of ischaemic stroke were confirmed by either computed tomography or magnetic resonance imaging. Myocardial infarction was diagnosed by the presence of clinical symptoms, elevated cardiac enzyme levels, and corresponding electrocardiographic changes. Exclusion criteria were TIA (defined as an event lasting < 24 h), haemorrhagic stroke, venous sinus thrombosis, carotid artery dissection, history of cardiovascular or cerebrovascular diseases, severe illness, aphasia, or cognitive impairment interfering with the questionnaire and not speaking Dutch. In summary, the RATIO study included young women (between 18 and 49 years old) with either a first myocardial infarction or ischaemic stroke (index events) who consecutively presented to one of the 16 participating hospitals in the Netherlands between 19.
Patient selection within the RATIO case-control study has been described in detail previously. For the present study two groups of patients, subjects who survived either a myocardial infarction or an ischaemic stroke, were included. We used data from the Risk of Arterial Thrombosis in Relation to Oral Contraceptives (RATIO) follow-up study, based on subjects who participated in the RATIO case-control study.
0 kommentar(er)
