title: Low positive predictive value of the ABCD2 score in emergency department transient ischaemic attack diagnoses: the South Western Sydney transient ischaemic attack study.
abstract: BACKGROUND
  The ABCD(2) stroke risk score is recommended in national guidelines for stratifying care in transient ischaemic attack (TIA) patients, based on its prediction of early stroke risk. We had become concerned about the score accuracy and its clinical value in modern TIA cohorts.
  
  
  METHODS
  We identified emergency department-diagnosed TIA at two hospitals over 3 years (2004-2006). Cases were followed for stroke occurrence and ABCD(2) scores were determined from expert record review. Sensitivity, specificity and positive predictive values (PPV) of moderate-high ABCD(2) scores were determined.
  
  
  RESULTS
  There were 827 indexed TIA diagnoses and record review was possible in 95.4%. Admitted patients had lower 30-day stroke risk (n = 0) than discharged patients (n = 7; 3.1%) (P < 0.0001). There was no significant difference in proportion of strokes between those with a low or moderate-high ABCD(2) score at 30 (1.2 vs 0.8%), 90 (2.0 vs 1.9%) and 365 days (2.4 vs 2.4%) respectively. At 30 days the sensitivity, specificity and PPV of a moderate-high score were 57% (95% confidence interval (CI) 25.0-84.2), 32.2% (95% CI 29.1-35.6) and 0.75% (95% CI 0.29-1.91) respectively.
  
  
  CONCLUSIONS
  Early stroke risk was low after an emergency diagnosis of TIA and significantly lower in admitted patients. Moderate-high ABCD(2) scores did not predict early stroke risk. We suggest local validation of ABCD(2) before its clinical use and a review of its place in national guidelines.
authors.affiliation: Neurology Department, Liverpool Hospital, Sydney, New South Wales, Australia.
authors.forename: D
authors.initials: D
authors.lastname: Ghia
authors.forename: P
authors.initials: P
authors.lastname: Thomas
authors.forename: D
authors.initials: D
authors.lastname: Cordato
authors.forename: D
authors.initials: D
authors.lastname: Epstein
authors.forename: R G
authors.initials: RG
authors.lastname: Beran
authors.forename: C
authors.initials: C
authors.lastname: Cappelen-Smith
authors.forename: N
authors.initials: N
authors.lastname: Griffith
authors.forename: I
authors.initials: I
authors.lastname: Hanna
authors.forename: A
authors.initials: A
authors.lastname: McDougall
authors.forename: S J
authors.initials: SJ
authors.lastname: Hodgkinson
authors.forename: J M
authors.initials: JM
authors.lastname: Worthington
mesh_terms: D000368:Aged; D015331:Cohort Studies; D016208:Databases, Factual; D004636:Emergency Service, Hospital / Q000639:trends; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009517:New South Wales / Q000453:epidemiology; D010343:Patient Admission / Q000639:trends; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D020521:Stroke / Q000453:epidemiology / Q000517:prevention & control