title: Diagnostic usefulness of the ABCD2 score to distinguish transient ischemic attack and minor ischemic stroke from noncerebrovascular events: the North Dublin TIA Study.
abstract: OBJECTIVE
  Transient ischemic attack (TIA) diagnosis is frequently difficult in clinical practice. Noncerebrovascular symptoms are often misclassified as TIA by nonspecialist physicians. Clinical prediction rules such as ABCD(2) improve the identification of patients with TIA at high risk of early stroke. We hypothesized that the ABCD(2) score may partly improve risk stratification due to improved discrimination of true TIA and minor ischemic stroke (MIS) from noncerebrovascular events.
  
  
  METHODS
  Consecutive patients with TIA were identified within a prospective population-based cohort study of stroke and TIA. The cohort was expanded by inclusion of patients with MIS and noncerebrovascular events referred to a daily TIA clinic serving the population. Diagnosis was assigned by a trained stroke physician independent of ABCD(2) score.
  
  
  RESULTS
  Five hundred ninety-four patients were included (292 [49.2%] TIA, 45 [7.6%] MIS, and 257 [43.3%] noncerebrovascular). The mean ABCD(2) score showed a graded increase across diagnostic groups (MIS mean 4.8 [SD 1.4] versus TIA mean 3.9 [SD 1.5] versus noncerebrovascular mean 2.9 [SD 1.5]; P<0.00001). The ABCD(2) score discriminated well between noncerebrovascular and cerebrovascular events-TIA (c-statistic 0.68; 95% CI, 0.64 to 0.72), any vascular event (TIA+MIS; c-statistic 0.7; 95% CI, 0.66 to 0.74), and MIS (c-statistic 0.81; 95% CI, 0.75 to 0.87)-from noncerebrovascular events. Of ABCD(2) items, unilateral weakness (OR, 4.5; 95% CI, 3.1 to 6.6) and speech disturbance (OR, 2.5; 95% CI, 1.6, 4.1) were most likely overrepresented in TIA compared with noncerebrovascular groups.
  
  
  CONCLUSIONS
  The ABCD(2) score had significant diagnostic usefulness for discrimination of true TIA and MIS from noncerebrovascular events, which may contribute to its predictive usefulness.
authors.affiliation: Neurovascular Clinical Science Unit, Mater University Hospital, University College Dublin, Dublin, Ireland.
authors.forename: Orla C
authors.initials: OC
authors.lastname: Sheehan
authors.forename: Aine
authors.initials: A
authors.lastname: Merwick
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Kelly
authors.forename: Niamh
authors.initials: N
authors.lastname: Hannon
authors.forename: Michael
authors.initials: M
authors.lastname: Marnane
authors.forename: Lorraine
authors.initials: L
authors.lastname: Kyne
authors.forename: Patricia M E
authors.initials: PM
authors.lastname: McCormack
authors.forename: Joseph
authors.initials: J
authors.lastname: Duggan
authors.forename: Alan
authors.initials: A
authors.lastname: Moore
authors.forename: Joan
authors.initials: J
authors.lastname: Moroney
authors.forename: Leslie
authors.initials: L
authors.lastname: Daly
authors.forename: Dawn
authors.initials: D
authors.lastname: Harris
authors.forename: Gillian
authors.initials: G
authors.lastname: Horgan
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Kelly
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000175:diagnosis / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D002546:Ischemic Attack, Transient / Q000175:diagnosis* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012107:Research Design / Q000592:standards*; D020521:Stroke / Q000175:diagnosis* / Q000453:epidemiology