Advertisement
Heart, Lung and Circulation

Māori Health Outcomes in Intensive Care Following Cardiac Surgery in Aotearoa New Zealand

Published:March 03, 2022DOI:https://doi.org/10.1016/j.hlc.2021.11.015

      Background

      Māori, the indigenous peoples of Aotearoa New Zealand (NZ) experience disproportionately worse outcomes in cardiovascular health compared to non-Māori. Waikato Hospital provides tertiary cardiothoracic services to the Midland region of NZ, and has instituted an official policy to eliminate ethnic inequity in health. We aimed to audit the outcomes of our cardiothoracic intensive care unit (ICU) against this standard.

      Method

      We analysed data from the prospectively-entered Australia and NZ Intensive Care Society database for all planned cardiothoracic ICU admissions from 2014 to 2018 at Waikato Hospital for patients aged 15-years and older (n=2,736). Outcomes measured were in-ICU, in-hospital, and 1-year mortality.

      Results

      Māori were under-represented in this cohort (17.9%) compared to the general Midland population. Māori patients were younger (median 60 vs 68-years old, p<0.001), were more commonly female (34.8% vs 23.6%, p<0.001), domiciled in more deprived areas (2018 NZ Index of Deprivation of 9 vs 6, p<0.001), and more likely to have rheumatic heart disease (35.6% vs 16.6%, p<0.001). More non-Māori required coronary vessel only surgery (57.4% vs 45.2%), whilst more Māori required valvular only surgery (41.1% vs 31.2%) (p<0.001 overall). Baseline Acute Physiology and Chronic Health Evaluation (APACHE) III risk of death score was higher for Māori (1.53% vs 0.89%, p<0.001), as was the European System for Cardiac Operative Risk Evaluation (EuroSCORE) II (2.04% vs 1.55%, p<0.001). Unadjusted mortality was higher for Māori in-ICU (3.1% vs 1.3%, p=0.005) and at 1-year (7.1% vs 3.8%, p=0.002). Adjusted in-ICU mortality, however, was predicted by combined coronary-valvular surgery (adjusted odds ratio, AOR 25.5 [95% confidence interval (CI) 3.30–348.46], p=0.005), Australia and New Zealand Risk of Death (ANZROD) score (AOR 1.11 [CI 1.05–1.19] p<0.001), and renal replacement therapy requirement (AOR 154.56 [CI 30.86–1,107.17] p<0.001), but not by Māori ethnicity (AOR 0.27 [CI 0.03–1.43] p=0.156).

      Conclusion

      Our audit has identified significant inequity for Māori at our cardiothoracic ICU. Māori are sicker on presentation for planned cardiac surgery, as evidenced by higher admission severity scores, and experience higher unadjusted mortality up to 1-year compared to non-Māori. Māori also appear under-represented despite a greater burden of cardiovascular disease in the community. Further study is required to identify if upstream risk factors, including failure of early detection and referral for disease, contribute to these findings.

      Keywords

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Heart, Lung and Circulation
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Roth G.A.
        • Mensah G.A.
        • Johnson C.O.
        • Addolorato G.
        • Ammirati E.
        • Baddour L.M.
        • et al.
        Global burden of cardiovascular diseases and risk factors, 1990–2019.
        J Am Coll Cardiol. 2020; 76: 2982-3021
        • Anand S.S.
        • Abonyi S.
        • Arbour L.
        • Balasubramaniam K.
        • Brook J.
        • Castleden H.
        • et al.
        Explaining the variability in cardiovascular risk factors among First Nations communities in Canada: a population-based study.
        Lancet Planet Health. 2019; 3: e511-e520
        • Reath J.S.
        • O’Mara P.
        Closing the gap in cardiovascular risk for Aboriginal and Torres Strait Islander Australians.
        Med J Aust. 2018; 209: 17-18
        • Breathett K.
        • Sims M.
        • Gross M.
        • Jackson E.A.
        • Jones E.J.
        • Navas-Acien A.
        • et al.
        Cardiovascular health in American Indians and Alaska Natives: a scientific statement from the American Heart Association.
        Circulation. 2020; 141: E948-E959
        • Fawcett J.
        • Blakely T.
        • Robson B.
        • Tobias M.
        • Harris R.
        • Pakipaki N.
        Decades of disparity III: ethnic and socioeconomic inequalities in mortality, New Zealand 1981–1999.
        (Wellington)
        https://www.otago.ac.nz/wellington/otago024509.pdf
        Date: May 2006
        Date accessed: March 31, 2020
      1. Robson B. Harris R. Hauora: Māori Standards of Health IV. A study of the years 2000-2005. Te Rōpū Rangahau Hauora a Eru Pōmare, Welington2007
        • Ministry of Health
        Wai 2575 Māori Health Trends Report.
        Ministry of Health, Wellington2019
        • Heart Foundation of New Zealand
        New Zealand Guidelines for rheumatic fever: diagnosis, management and secondary prevention of acute rheumatic fever and rheumatic heart disease: 2014 Update.
        (Auckland)
        www.heartfoundation.org.nz
        Date: 2014
        Date accessed: January 19, 2021
        • Bramley D.
        • Riddell T.
        • Crengle S.
        • Curtis E.
        • Harwood M.
        • Nehua D.
        • et al.
        A call to action on Maori cardiovascular health.
        N Z Med J. 2004; 117: U957
        • Stats N.Z.
        District Health Boards ethnic group population projections produced by Statistics New Zealand according to assumptions agreed to by the Ministry of Health.
        2018
        • Waikato District Health Board
        Healthy people, excellent care: Waikato District Health Board Strategy.
        (Hamilton)
        www.waikatodhb.health.nz/strategy
        Date: July 2016
        Date accessed: May 12, 2020
        • Benjamin A.
        The competent novice. Audit: how to do it in practice.
        BMJ. 2008; 336: 1241-1245
        • Australia and New Zealand Intensive Care Society
        ANZICS Centre for Outcome and Resource Evaluation APD Data Dictionary Version 5.10: COMET Release.
        Camberwell, Victoria2020
        • Knaus W.A.
        • Draper E.A.
        • Wagner D.P.
        • Zimmerman J.E.
        APACHE II: a severity of disease classification system.
        Crit Care Med. 1985; 13: 818-829
        • Knaus W.A.
        • Wagner D.P.
        • Draper E.A.
        • Zimmerman J.E.
        • Bergner M.
        • Bastos P.G.
        • et al.
        The APACHE III prognostic system: risk prediction of hospital mortality for critically III hospitalized adults.
        Chest. 1991; 100: 1619-1636
        • Paul E.
        • Bailey M.
        • Pilcher D.
        Risk prediction of hospital mortality for adult patients admitted to Australian and New Zealand intensive care units: development and validation of the Australian and New Zealand Risk of Death model.
        J Crit Care. 2013; 28: 935-941
        • Nashef S.A.M.
        • Roques F.
        • Sharples L.D.
        • Nilsson J.
        • Smith C.
        • Goldstone A.R.
        • et al.
        Euroscore II.
        Eur J Cardiothorac Surg. 2012; 41: 734-745
        • Ministry of Health
        National Health Index data dictionary (Version 5.3).
        July 2009 (Wellington)
        • Edwards P.
        • Lawrenson R.
        • Jelley G.
        Midland Region DHBs: Defining Midland region localities.
        Midland Healthshare, Hamilton, New Zealand2014 Feb 1
        • Anderson I.
        • Crengle S.
        • Kamaka M.L.
        • Chen T-H.
        • Palafox N.
        • Jackson-Pulver L.
        Indigenous health in Australia, New Zealand, and the Pacific.
        Lancet. 2006; 367: 1775-1785
        • Blakely T.
        • Fawcett J.
        • Hunt D.
        • Wilson N.
        What is the contribution of smoking and socioeconomic position to ethnic inequalities in mortality in New Zealand?.
        Lancet. 2006; 368: 44-52
        • Disney G.
        • Teng A.
        • Atkinson J.
        • Wilson N.
        • Blakely T.
        Changing ethnic inequalities in mortality in New Zealand over 30 years: linked cohort studies with 68.9 million person-years of follow-up.
        Popul Health Metr. 2017; 15: 15
        • Grey C.
        • Jackson R.
        • Wells S.
        • Marshall R.
        • Mehta S.
        • Kerr A.J.
        Ethnic differences in case fatality following an acute ischaemic heart disease event in New Zealand: ANZACS-QI 13.
        Eur J Prev Cardiol. 2016; 23: 1823-1830
        • Tukuitonga C.
        • Bindman A.
        Ethnic and gender differences in the use of coronary artery revascularisation procedures in New Zealand.
        N Z Med J. 2002; 115: 179-182
        • Grey C.
        • Jackson R.
        • Wells S.
        • Randall D.
        • Harwood M.
        • Mehta S.
        • et al.
        Ethnic differences in coronary revascularisation following an acute coronary syndrome in New Zealand: a national data-linkage study (ANZACS-QI 12).
        Heart Lung Circ. 2016; 25: 820-828
        • Milne R.J.
        • Lennon D.
        • Stewart J.M.
        • Hoorn S.V.
        • Scuffham P.A.
        Mortality and hospitalisation costs of rheumatic fever and rheumatic heart disease in New Zealand.
        J Paediatr Child Health. 2012; 48: 692-697
        • White H.
        • Walsh W.
        • Brown A.
        • Riddell T.
        • Tonkin A.
        • Jeremy R.
        • et al.
        Rheumatic heart disease in indigenous populations.
        Heart Lung Circ. 2010; 19: 273-281
        • New Zealand National Cardiac Surgery Clinical Network
        Cardiac Surgery in New Zealand Public Hospitals: 2018 Annual Report.
        Ministry of Health, Wellington2018
        • Seddon M.
        • Broad J.
        • Crengle S.
        • Bramley D.
        • Jackson R.
        • White H.
        Coronary artery bypass graft surgery in New Zealand’s Auckland region: a comparison between the clinical priority assessment criteria score and the actual clinical priority assigned.
        N Z Med J. 2006; 119: U1881
        • Sandiford P.
        • El-Jack S.S.
        • Scott A.G.
        • Crengle S.M.
        • Bramley D.
        Different needs or treated differently? understanding ethnic inequalities in coronary revascularisation rates.
        Heart Lung Circ. 2015; 24: 960-968
        • Kerr A.J.
        • Mustafa A.
        • Lee M.
        • Wells S.
        • Grey C.
        • Riddell T.
        • et al.
        Ethnicity and revascularisation following acute coronary syndromes: a 5-year cohort study (ANZACS-QI-3).
        N Z Med J. 2014; 127: 38-51
        • Ellis C.
        • Devlin G.
        • Matsis P.
        • Elliott J.
        • Williams M.
        • Gamble G.
        • et al.
        Acute coronary syndrome patients in New Zealand receive less invasive management when admitted to hospitals without invasive facilities.
        N Z Med J. 2004; 117: U954
        • Ellis C.
        • Devlin G.
        • Elliott J.
        • Matsis P.
        • Williams M.
        • Gamble G.
        • et al.
        ACS patients in New Zealand experience significant delays to access cardiac investigations and revascularisation treatment especially when admitted to non-interventional centres: results of the second comprehensive national audit of ACS patients.
        N Z Med J. 2010; 123: 44-60
        • Wang T.K.M.
        • Ramanathan T.
        • Stewart R.
        • Crengle S.
        • Gamble G.
        • White H.
        Māori have worse outcomes after coronary artery bypass grafting than Europeans in New Zealand.
        N Z Med J. 2013; 126: 12-22
        • McBride K.F.
        • Rolleston A.
        • Grey C.
        • Howard N.J.
        • Paquet C.
        • Brown A.
        Māori, Pacific, Aboriginal and Torres Strait Islander women’s cardiovascular health: where are the opportunities to make a real difference?.
        Heart Lung Circ. 2021; 30: 52-58
        • Stehli J.
        • Duffy S.J.
        • Burgess S.
        • Kuhn L.
        • Gulati M.
        • Chow C.
        • et al.
        Sex disparities in myocardial infarction: biology or bias?.
        Heart Lung Circ. 2021; 30: 18-26
        • Koh Y.
        • Stehli J.
        • Martin C.
        • Brennan A.
        • Dinh D.T.
        • Lefkovits J.
        • et al.
        Does sex predict quality of life after acute coronary syndromes: an Australian, state-wide, multicentre prospective cohort study.
        BMJ Open. 2019; 9: 34034
        • Burgess S.N.
        • Juergens C.P.
        • Nguyen T.L.
        • Leung M.
        • Robledo K.P.
        • Thomas L.
        • et al.
        Comparison of late cardiac death and myocardial infarction rates in women vs men with ST-elevation myocardial infarction.
        Am J Cardiol. 2020; 128: 120-126
        • Mohd Slim M.A.
        • Lala H.M.
        • Barnes N.
        • Martynoga R.A.
        Māori health outcomes in an intensive care unit in Aotearoa New Zealand.
        Anaesth Intensive Care. 2021; 49: 292-300
        • Walsh M.
        • Grey C.
        The contribution of avoidable mortality to the life expectancy gap in Māori and Pacii c populations in New Zealand-a decomposition analysis.
        NZMJ. 2019; 132: 1492
        • Woodward A.
        • Kawachi I.
        Why reduce health inequalities?.
        J Epidemiol Community Health. 2000; 54: 923-929
        • Pickett K.E.
        • Wilkinson R.G.
        Income inequality and health: a causal review.
        Soc Sci Med. 2015; 128: 316-326
        • Koea J.
        • Ronald M.
        What do indigenous communities want from their surgeons and surgical services: a systematic review.
        Surg. 2020; 167: 661-667
        • Oetzel J.G.
        Addressing health inequities in cardiovascular health in Indigenous communities: Implementation process matters as much as the intervention itself.
        Int J Cardiol. 2018; 269: 325-326
        • Reid P.
        • Paine S.-J.
        • Curtis E.
        • Jones R.
        • Anderson A.
        • Willing E.
        • et al.
        Achieving health equity in Aotearoa: strengthening responsiveness to Māori in health research.
        N Z Med J. 2017; 130: 96-103
        • Chan J.C.Y.
        • Gupta A.K.
        • Stewart S.K.
        • McCulloch G.A.J.
        • Babidge W.J.
        • Worthington M.G.
        • et al.
        Mortality in Australian cardiothoracic surgery: findings from a national audit.
        Ann Thorac Surg. 2020; 109: 1880-1888
        • Singh N.
        • Gimpel D.
        • Parkinson G.
        • Conaglen P.
        • Meikle F.
        • Lin Z.
        • et al.
        Assessment of the EuroSCORE II in a New Zealand Tertiary Centre.
        Heart Lung Circ. 2019; 28: 1670-1676
        • Singh N.
        • Gimpel D.
        • Manikavasagar V.
        • Watson N.
        • Roberts J.
        • Conaglen P.
        • et al.
        Performance of the AusSCORE II and STS Score for coronary artery bypass grafting in a New Zealand population.
        Heart Lung Circ. 2021; 30: 600-604