title: Very early risk of stroke after a first transient ischemic attack.
abstract: OBJECTIVE
  The commonly quoted early risks of stroke after a first transient ischemic attack (TIA)-1% to 2% at 7 days and 2% to 4% at 1 month-are likely to be underestimates because of the delay before inclusion into previous studies and the exclusion of patients who had a stroke during this time. Therefore, it is uncertain how urgently TIA patients should be assessed. We used data from the Oxford Community Stroke Project (OCSP) to estimate the very early stroke risk after a TIA and investigated the potential effects of the delays before specialist assessment.
  
  
  METHODS
  All OCSP patients who had a first-ever definite TIA during the study period (n=209) were included. Three analyses were used to estimate the early stroke risk after a first TIA starting from 3 different dates: assessment by a neurologist, referral to the TIA service, and onset of first TIA.
  
  
  RESULTS
  The stroke risk from assessment by a neurologist was 1.9% [95% confidence interval (CI), 0.1 to 3.8] at 7 days and 4.4% (95% CI, 1.6 to 7.2) at 30 days. The 7- and 30-day stroke risks from referral were 2.4% (95% CI, 0.3 to 4.5) and 4.9% (95% CI, 1.9 to 7.8), respectively, and from onset of first-ever TIA were 8.6% (95% CI, 4.8 to 12.4) and 12.0% (95% CI, 7.6 to 16.4), respectively.
  
  
  CONCLUSIONS
  The early risk of stroke from date of first-ever TIA is likely to be higher than commonly quoted. Public education about the symptoms of TIA is needed so that medical attention is sought more urgently and stroke prevention strategies are implemented sooner.
authors.affiliation: Stroke Prevention Research Unit, Department of Clinical Neurology, Radcliffe Infirmary, Woodstock Rd, Oxford OX2 6HE UK.
authors.forename: J K
authors.initials: JK
authors.lastname: Lovett
authors.forename: M S
authors.initials: MS
authors.lastname: Dennis
authors.forename: P A G
authors.initials: PA
authors.lastname: Sandercock
authors.forename: J
authors.initials: J
authors.lastname: Bamford
authors.forename: C P
authors.initials: CP
authors.lastname: Warlow
authors.forename: P M
authors.initials: PM
authors.lastname: Rothwell
mesh_terms: D000368:Aged; D015984:Causality; D015897:Comorbidity / Q000639:trends; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000453:epidemiology*; D008297:Male; D011446:Prospective Studies; D012017:Referral and Consultation / Q000706:statistics & numerical data; D018570:Risk Assessment; D020521:Stroke / Q000453:epidemiology* / Q000517:prevention & control; D016019:Survival Analysis; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology