title: Evaluation of the NICE mini-GRACE risk scores for acute myocardial infarction using the Myocardial Ischaemia National Audit Project (MINAP) 2003-2009: National Institute for Cardiovascular Outcomes Research (NICOR).
abstract: OBJECTIVE
  To evaluate the performance of the National Institute for Health and Clinical Excellence (NICE) mini-Global Registry of Acute Coronary Events (GRACE) (MG) and adjusted mini-GRACE (AMG) risk scores.
  
  
  METHODS
  Retrospective observational study.
  
  
  METHODS
  215 acute hospitals in England and Wales.
  
  
  METHODS
  137 084 patients discharged from hospital with a diagnosis of acute myocardial infarction (AMI) between 2003 and 2009, as recorded in the Myocardial Ischaemia National Audit Project (MINAP).
  
  
  METHODS
  Model performance indices of calibration accuracy, discriminative and explanatory performance, including net reclassification index (NRI) and integrated discrimination improvement.
  
  
  RESULTS
  Of 495 263 index patients hospitalised with AMI, there were 53 196 ST elevation myocardial infarction and 83 888 non-ST elevation myocardial infarction (NSTEMI) (27.7%) cases with complete data for all AMG variables. For AMI, AMG calibration was better than MG calibration (Hosmer-Lemeshow goodness of fit test: p=0.33 vs p<0.05). MG and AMG predictive accuracy and discriminative ability were good (Brier score: 0.10 vs 0.09; C statistic: 0.82 and 0.84, respectively). The NRI of AMG over MG was 8.1% (p<0.05). Model performance was reduced in patients with NSTEMI, chronic heart failure, chronic renal failure and in patients aged ≥85 years.
  
  
  CONCLUSIONS
  The AMG and MG risk scores, utilised by NICE, demonstrated good performance across a range of indices using MINAP data, but performed less well in higher risk subgroups. Although indices were better for AMG, its application may be constrained by missing predictors.
authors.affiliation: Centre for Epidemiology and Biostatistics, University of Leeds, Leeds, UK. simmsy@doctors.org.uk
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Simms
authors.forename: Stephanie
authors.initials: S
authors.lastname: Reynolds
authors.forename: Karen
authors.initials: K
authors.lastname: Pieper
authors.forename: Paul D
authors.initials: PD
authors.lastname: Baxter
authors.forename: Brian A
authors.initials: BA
authors.lastname: Cattle
authors.forename: Phillip D
authors.initials: PD
authors.lastname: Batin
authors.forename: John I
authors.initials: JI
authors.lastname: Wilson
authors.forename: John E
authors.initials: JE
authors.lastname: Deanfield
authors.forename: Robert M
authors.initials: RM
authors.lastname: West
authors.forename: Keith A A
authors.initials: KA
authors.lastname: Fox
authors.forename: Alistair S
authors.initials: AS
authors.lastname: Hall
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Gale
mesh_terms: D000047:Academies and Institutes; D000368:Aged; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008485:Medical Audit; D009203:Myocardial Infarction / Q000145:classification / Q000175:diagnosis* / Q000401:mortality; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011379:Prognosis; D012042:Registries; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D015996:Survival Rate; D013997:Time Factors; D014852:Wales / Q000453:epidemiology