Population based study of early risk of stroke after transient ischaemic attack or minor stroke: implications for public education and organisation of services

Objective To estimate the very early stroke risk after a transient ischaemic attack (TIA) or minor stroke and thereby inform the planning of effective stroke prevention services. Design Population based prospective cohort study of patients with TIA, or stroke. Setting Nine general practices in Oxfordshire, England, from April 2002 to April 2003. Participants All patients who had a TIA (n=87) or minor stroke (n=87) during the study period and who presented to medical attention. Main outcome measures Risk of recurrent stroke at seven days, one month, and three months after TIAs and minor strokes. Results The estimated risk of recurrent stroke was 8.0% (95% confidence interval 2.3% to 13.7%) at seven days, 11.5% (4.8% to 18.2%) at one month, and 17.3% (9.3% to 25.3%) at three months after a TIA. The risks at these three time periods after a minor stroke were 11.5% (4.8% to 11.2%),15.0% (7.5% to 22.5% and 18.5% (10.3% to 26.7%). Conclusions The early risks of stroke after a TIA or minor stroke are much higher than commonly quoted. More research is needed to determine whether these risks can be reduced by more rapid instigation of preventive treatment.