Aboriginal to non-Aboriginal differentials in 2-year outcomes following non-fatal first-ever acute MI persist after adjustment for comorbidity

Abstract

Background: We investigated the relationship between Aboriginality and 2-year cardiovascular disease outcomes in non-fatal first-ever myocardial infarction during 2000⊟04, with progressive adjustment of covariates, including comorbidities.

Design: Historical cohort study.

Methods: Person-linked hospital and mortality records were used to identify 28-day survivors of first-ever myocardial infarction in Western Australia during 2000⊟04 with 15-year lookback. The outcome measures were: (1) cardiovascular disease death; (2) recurrent admission for myocardial infarction; and (3) the composite of (1) and (2).

Results: Compared with non-Aboriginal patients, Aboriginals were younger and more likely to live remotely. The proportions having 5-year histories of diabetes and chronic kidney disease were double and triple those of non-Aboriginals. When adjusting for demographic variables alone, the Aboriginal to non-Aboriginal hazard ratios for cardiovascular death or recurrent myocardial infarction were 3.6 (95% CI 2.5–5.3) in men and 4.5 (95% CI 2.8–7.3) in women. After adjustment for comorbidities, including diabetes, chronic kidney disease and heart failure, the hazard ratios decreased 36% and 47% to 2.3 (1.6–3.0) and 2.4 (1.5–4.0) in males and females, respectively.

Conclusions: The high prevalence of comorbidities in Aboriginal people, including diabetes, kidney disease, heart failure, and other risk factors contribute substantially to the disparity in post-myocardial infarction outcomes in Aboriginal people, reinforcing the importance of both primary prevention and comprehensive management of chronic conditions in this population. Aboriginality remains a significant independent risk factor for disease recurrence or mortality, even after adjusting for comorbidity, suggesting the need for society-level interventions addressing social disadvantage.

Keywords

Aboriginal cardiovascular outcomes myocardial infarction social differentials

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References

Barakat

Stevenson

Wilkinson

Suliman

Ranjadayalan

Timmis

. Socioeconomic differentials in recurrent ischaemia and mortality after acute myocardial infarction. Heart 2001; 85(4): 390–394.

Iribarren

Tolstykh

Somkin

Ackerson

Brown

Scheffler

. Sex and racial/ethnic disparities in outcomes after acute myocardial infarction: a cohort study among members of a large integrated health care delivery system in northern California. Arch Intern Med 2005; 165(18): 2105–2113.

Plakht

Gilutz

Shiyovich

Zahger

Weitzman

. Gender and ethnic disparities in outcome following acute myocardial infarction among Bedouins and Jews in southern Israel. Euro J Public Health 2011; 21(1): 74–80.

Salomaa

Miettinen

Niemela

Ketonen

Mahonen

Immonen-Raiha

. Relation of socioeconomic position to the case fatality, prognosis and treatment of myocardial infarction events; the FINMONICA MI Register Study. J Epidemiol Community Health 2001; 55(7): 475–482.

Spertus

. Broadening our understanding of survival after myocardial infarction: the association of neighborhood with outcomes. Circulation 2010; 121(3): 348–350.

Weintraub

Vaccarino

. Explaining racial disparities in coronary outcomes in women. Circulation 2003; 108(9): 1041–1043.

Bradshaw

Alfonso

Finn

Owens

Thompson

. Coronary heart disease events in Aboriginal Australians: incidence in an urban population. Med J Aust 2009; 190(10): 583–586.

Brown

. Acute coronary syndromes in indigenous Australians: opportunities for improving outcomes across the continuum of care. Heart Lung Circ 2010; 19: 325–336.

Katzenellenbogen

Sanfilippo

Hobbs

MST

Briffa

Ridout

Knuiman

. Incidence of and case fatality following acute myocardial infarction in Aboriginal and non-Aboriginal Western Australians (2000–2004): a linked data study. Heart Lung Circ 2010; 19: 717–725.

10.

You

Condon

Zhao

Guthridge

. Incidence and survival after acute myocardial infarction in Indigenous and non-Indigenous people in the Northern Territory, 1992⊟2004. Med J Australia 2009; 190(6): 298–302.

11.

Mathur

Moon

Leigh

. Aboriginal and Torres Strait Islander people with coronary heart disease: Further perspectives on health status and treatment , Canberra: Australian Institute of Health and Welfare, 2006.

12.

Vos

Barker

Begg

Stanley

Lopez

. Burden of disease and injury in Aboriginal and Torres Strait Islander Peoples: the Indigenous health gap. Int J Epidemiol 2009; 38(2): 470–477.

13.

Cass

Gillin

Horvath

. End-stage renal disease in Aboriginals in New South Wales: a very different picture to the Northern Territory. Med J Aust 1999; 171: 407–410.

14.

Tong

Stevenson

. Comorbidity of cardiovascular disease, diabetes and chronic kidney disease in Australia , Canberra: Australian Institute of Health and Welfare, 2007.

15.

Wang

Hoy

. Association between diabetes and coronary heart disease in Aboriginal people: are women disadvantaged? Med J Aust 2004; 180: 508–511.

16.

CHY

Zinman

. Type 2 diabetes and impaired glucose tolerance in aboriginal populations: a global perspective. Diabetes Res Clin Pract 2007; 78: 159–170.

17.

National Center for Health Statistics. International classification of diseases, 9th revision, clinical modification: ICD-9-CM annotated diseases , Ann Arbor, Michigan: Commission on Professional and Hospital Activities, 1986.

18.

Holman

Bass

Rouse

Hobbs

. Population-based linkage of health records in Western Australia: development of a health services research linked database. Aust NZ J Public Health 1999; 23(5): 453–459.

19.

Briffa T, Sanfilippo F, Hobbs M, Ridout S, Katzenellenbogen J, Thompson P, et al. Under-ascertainment of Aboriginality in records of cardiovascular disease in hospital morbidity and mortality data in Western Australia: a record linkage study. BMC Med Res Methodol 2010; 10(1): 111.

20.

Australian Institute of Health and Welfare. National best practice guidelines for collecting indigenous status in health data sets , Canberra: Australian Institute of Health and Welfare, 2010.

21.

Australian Bureau of Statistics. Australian Standard Geographical Classification (ASGC) 2001 , Canberra: Australian Bureau of Statistics, 2001.

22.

Adhikari

. Socio-economic indices for areas: Introduction, use and future direction , Canberra: Australian Bureau of Statistics, 2006.

23.

Charlson

Pompei

Ales

MacKenzie

. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chron Dis 1987; 40(5): 373–383.

24.

Sanfilippo FM, Hobbs MST, Knuiman MW, Ridout SC, Bradshaw PJ, Finn JC, et al. Can we monitor heart attack in the troponin era: evidence from a population-based cohort study. BMC Cardiovasc Disord 2011; 11(1): 35.

25.

Brown

. Bridging the survival gap between indigenous and non-indigenous Australians: priorities for the road ahead. Heart Lung Circ 2009; 18: 96–100.

26.

Lawrence

Holman

Jablensky

Hobbs

. Death rate from ischaemic heart disease in Western Australian psychiatric patients 1980–1998. Br J Psychiatry 2003; 182: 31–36.

27.

Australian Bureau of Statistics. National Aboriginal and Torres Strait Islander Health Survey 2004–2005 , Canberra: Australian Bureau of Statistics, 2006.

28.

Brown

Morrissey

Sherwood

Brown

Morrissey

Sherwood

. Uncovering the determinants of cardiovascular disease among indigenous people. Ethn Health 2006; 11(2): 191–210.

29.

Cass

Cunningham

Snelling

Wang

Hoy

Cass

. Exploring the pathways leading from disadvantage to end-stage renal disease for indigenous Australians. Soc Sc Med 2004; 58(4): 767–785.

30.

Marmot

. Social determinants of health inequalities. Lancet 2005; 365: 1099–1104.

31.

O’Dea

Rowley

Brown

O’Dea

Rowley

Brown

. Diabetes in indigenous Australians: possible ways forward. Med J Aust 2007; 186(10): 494–495.

32.

Reath

Brown

. Managing cardiovascular disease in Aboriginal and Torres Strait Islander people. Australian Prescriber 2010; 33(3): 72–75.

33.

Weeramanthri

. The Northern Territory Preventable Chronic Disease Strategy−promoting an integrated and life course approach to chronic disease in Australia. Aust Health Rev 2003; 26(3): 31–31.

34.

Beauchamp A, Peeters A, Tonkin A and Turrell G. Best practice for prevention and treatment of cardiovascular disease through an equity lens: a review. Euro J Cardiovasc Prev Rehabil 2010 Oct;17(5): 599 606.

35.

Yancy

Wang

Ventura

Pina

Vijayaraghavan

Ferdinand

. The coalition to reduce racial and ethnic disparities in cardiovascular disease outcomes (credo): why credo matters to cardiologists. J Am Coll Cardiol 2011; 57(3): 245–252.

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