title: Validation study of GRACE risk scores in indigenous and non-indigenous patients hospitalized with acute coronary syndrome.
abstract: BACKGROUND
  Although cardiovascular disease is the major cause of premature death among Indigenous peoples in several advanced economies, no acute coronary syndrome (ACS) risk models have been validated in Indigenous populations. We tested the validity and calibration of three Global Registry of Acute Coronary Events (GRACE) scores among Aboriginal and non-Aboriginal Australians.
  
  
  METHODS
  GRACE scores were calculated at admission or discharge using clinical data, with all-cause deaths obtained from data linkage. Scores for GRACE models were validated for; 1) in-hospital death, 2) death within 6 months from admission or 3) death within 6 months of discharge (this also for 1 and 5-years mortality).
  
  
  RESULTS
  Aboriginal patient were younger (62 % aged <55 years versus 15 % non-Aboriginal) and their median GRACE scores lower than non-Aboriginal patients, as was crude mortality at 6 months from admission (6 % vs 10 %) and at 1 and 5 years. After age stratification, risk scores for Aboriginal patients were equivalent or higher, especially among those aged <55 years. There was a trend to more deaths after discharge among Aboriginal patients in each age group, suggesting an age-related under-estimation of risk. The c-statistics for the three GRACE models within both groups were between 0.75 and 0.79.
  
  
  CONCLUSIONS
  We demonstrated for the first time that while the discriminatory capacity of GRACE risk scores among Indigenous Australians is good, the models may need re-calibrating to improve risk stratification in this and other Indigenous groups, where age of onset of coronary disease is much younger than among the original reference population.
authors.affiliation: School of Population Health, University of Western Australia, M431, 35 Stirling Highway, Crawley, WA, 6009, Australia. pamela.bradshaw@uwa.edu.au.|Western Australian Centre for Rural Health, University of Western Australia, M706, 35 Stirling Highway, Crawley, WA, 6009, Australia. pamela.bradshaw@uwa.edu.au.
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Bradshaw
authors.affiliation: Western Australian Centre for Rural Health, University of Western Australia, M706, 35 Stirling Highway, Crawley, WA, 6009, Australia. judith.katzenellenbogen@uwa.edu.au.
authors.forename: Judith M
authors.initials: JM
authors.lastname: Katzenellenbogen
authors.affiliation: School of Population Health, University of Western Australia, M431, 35 Stirling Highway, Crawley, WA, 6009, Australia. frank.sanfilippo@uwa.edu.au.
authors.forename: Frank M
authors.initials: FM
authors.lastname: Sanfilippo
authors.affiliation: School of Population Health, University of Western Australia, M431, 35 Stirling Highway, Crawley, WA, 6009, Australia. michael.hobbs@uwa.edu.au.
authors.forename: Michael S T
authors.initials: MS
authors.lastname: Hobbs
authors.affiliation: School of Population Health, University of Western Australia, M431, 35 Stirling Highway, Crawley, WA, 6009, Australia. peter.thompson@health.wa.gov.au.|Department of Research, 2nd Floor A Block (Mailbox 26), Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands, 6009, WA, Australia. peter.thompson@health.wa.gov.au.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Thompson
authors.affiliation: Western Australian Centre for Rural Health, University of Western Australia, M706, 35 Stirling Highway, Crawley, WA, 6009, Australia. sandra.thompson@uwa.edu.au.
authors.forename: Sandra C
authors.initials: SC
authors.lastname: Thompson
mesh_terms: D054058:Acute Coronary Syndrome / Q000175:diagnosis* / Q000208:ethnology* / Q000401:mortality / Q000628:therapy; D000328:Adult; D017668:Age of Onset; D000368:Aged; D001315:Australia / Q000453:epidemiology; D003661:Decision Support Techniques; D016002:Discriminant Analysis; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D010343:Patient Admission; D010351:Patient Discharge; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors