Ischemic stroke in young women: a nested case-control study using the UK General Practice Research Database

Abstract

Background and purpose: Estimates of the incidence of ischemic stroke in young women vary widely from 0.9 to 8.9 per 100,000 per year. This study was conducted to determine the incidence and risk factors for ischemic stroke in young women in the UK.

Methods: Women aged 15 to 49 with a first diagnosis and supporting evidence of ischemic stroke between January 1, 1992, and December 31, 1998, were identified from the UK General Practice Research Database. Age-specific incidence rates were calculated and a nested case-control study was conducted with up to 6 controls randomly selected and matched to each case by year of birth and general practice. Crude and adjusted odds ratios (ORs) were calculated using conditional logistic regression.

Results: The incidence of ischemic stroke was 3.56/100 000 per year. Factors associated with an increased risk were heart disease (OR, 10.5), heavy alcohol consumption (OR, 8.5), previous venous thromboembolism (OR, 6.2), treated diabetes mellitus (OR, 4.7), hypertension (OR, 4.6), migraine (OR, 2.3), and use of combined oral contraceptives (OR, 2.3). Light alcohol consumption was found to be protective (OR, 0.17).

Conclusions: The crude incidence rate was lower than previously reported for the USA and Europe but higher than that reported for the UK Oxford Region. This could be because of an under-representation of mild cases or because of a true lower incidence in the UK compared with the USA and the rest of Europe. The results of the case-control study are consistent with previous studies of ischemic stroke in young women.