title: The ABCD and ABCD2 as predictors of stroke in transient ischemic attack clinic outpatients: a retrospective cohort study over 14 years.
abstract: BACKGROUND
  The ABCD and ABCD2 scores have been validated for use as predictors of stroke in community populations up to 90 days after a transient ischemic attack (TIA). TIA outpatient clinics may see a selective group of patients who have not had an early stroke but may be at raised risk in the medium to long term and therefore benefit from preventive treatment.
  
  
  OBJECTIVE
  To describe the prognostic values of the ABCD and ABCD2 scores on long-term stroke risk.
  
  
  METHODS
  Retrospective cohort study of TIA clinic outpatients followed for up to 14 years.
  
  
  METHODS
  Absolute and relative stroke risks, Kaplan-Meier survival curves and cumulative stroke incidence were calculated. Receiver Operating Characteristic curves (ROCs) and areas under the curve were calculated for both scores.
  
  
  RESULTS
  Seven hundred and ninety-five patients were included and 138 (17.3%) experienced a stroke within 13.8 years follow-up after first TIA clinic visit, a crude risk of 26.3 per 1000 person-years. Compared with baseline scores of 0-2, risk ratios for ABCD of 3-4 were 2.95 (95% CI 1.52-6.40), and for 5-6 were 3.42 (95% CI 1.72-7.54); for the ABCD2, risk ratios for 3-4 were 2.68 (95% CI 1.37-5.84), and for 5-7 were 3.55 (95% CI 1.80-7.79). Scores of > or = 3 for either ABCD or ABCD2 predicted raised stroke risks at 90 days, 1, 5 and 10 years. Areas under the curve were 0.619 (95% CI 0.571-0.668) and 0.630 (95% CI 0.582-0.677) for the ABCD and ABCD2 scores, respectively.
  
  
  CONCLUSIONS
  ABCD and ABCD2 scores of > or = 3 may be clinically useful in identifying TIA outpatients at raised risk of stroke in the medium to long term.
authors.affiliation: Division of Community Based Sciences, Faculty of Medicine, University of Glasgow, Glasgow G12 8RZ, UK
authors.forename: J K
authors.initials: JK
authors.lastname: Harrison
authors.forename: B
authors.initials: B
authors.lastname: Sloan
authors.forename: J
authors.initials: J
authors.lastname: Dawson
authors.forename: K R
authors.initials: KR
authors.lastname: Lees
authors.forename: D S
authors.initials: DS
authors.lastname: Morrison
mesh_terms: D000368:Aged; D000554:Ambulatory Care Facilities; D015331:Cohort Studies; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000150:complications*; D008297:Male; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000209:etiology* / Q000517:prevention & control; D013997:Time Factors