Disparities in revascularization rates after acute myocardial infarction between aboriginal and non-aboriginal people in Australia

Effects of a culturally informed model of care for Aboriginal and Torres Strait Islander patients with acute coronary syndrome in a tertiary hospital in Australia: a pre-post, quasi-experimental, interventional study

BACKGROUND

Aboriginal and Torres Strait Islander (Indigenous) peoples with cardiac disease in Australia have worse outcomes than non-Indigenous people with cardiac disease. We hypothesised that the implementation of a culturally informed model of care for Indigenous patients hospitalised with acute coronary syndrome (ACS) would improve their clinical outcomes.

METHODS

For this pre-post, quasi-experimental, interventional study, cohorts of Indigenous patients before and after the implementation of a model of care were compared. The novel, culturally informed, multidisciplinary-team model of care was a local programme of care developed to reduce morbidity and mortality from cardiac conditions among Indigenous Australians. All index admissions in the 24-month pre-implementation period (Jan 1 2013, to Dec 31, 2014) were analysed, as were all index admissions in the 12-month post-implementation period (Oct 1, 2015, to Sept 30, 2016). Comparisons were also made with non-Indigenous cohorts in the same timeframes. Admissions were excluded if the patient did not survive to hospital discharge. The study was conducted at Princess Alexandra Hospital, a tertiary hospital in metropolitan Brisbane (QLD, Australia). Data on presentation, comorbidities, investigations, treatment, and for outcomes were manually collected from a consolidated clinical information application. Mortality data were obtained from the Queensland Registry of Births, Deaths, and Marriages. The primary outcome was a composite of death, acute myocardial infarction, unplanned revascularisation, and cardiac readmission at 90 days after index admission, assessed in all patients.

FINDINGS

The Indigenous cohorts included 199 patients admitted with ACS before the model of care was implemented (85 [43%] were female and 114 [57%] were male) and 119 admitted post-implementation (62 [52%] were female and 57 [48%] were male). The non-Indigenous cohorts included 440 patients with ACS before the model of care was implemented (140 [32%] were female and 300 [68%] were male) and 467 admitted post-implementation (143 [31%] were female and 324 [69%] were male). Compared with the pre-implementation group, Indigenous patients admitted post-implementation had a significant reduction in the primary outcome (67 [34%] of 199 vs 24 [20%] of 119; hazard ratio 0·60, 95% CI 0·40-0·90; p=0·012), which was driven by a reduction in unplanned cardiac readmissions (64 [32%] of 199 vs 21 [18%] of 119; 0·55, 0·35-0·85; p=0·0060). There was no significant change in non-Indigenous patients between the pre-implementation and post-implementation timeframes in the composite endpoint at 90 days (81 [18%] of 440 vs 93 [20%] of 467; 1·08, 0·83-1·41; p=0·54). Pre-implementation, there was significantly more incidence of the primary outcome in Indigenous patients than non-Indigenous patients (p<0·0001), with no significant difference in the post-implementation period (p=0·92).

INTERPRETATION

Clinical outcomes for Indigenous patients admitted to a tertiary hospital in Australia improved after implementation of a culturally informed model of care, with a reduction in the disparity in incidence of primary endpoints that existed between Indigenous and non-Indigenous patients before implementation.

FUNDING

Queensland Department of Health Aboriginal and Torres Strait Islander Health Division (now First Nations Health Office).

In-hospital outcomes by insurance type among patients undergoing percutaneous coronary interventions for acute myocardial infarction in New South Wales public hospitals

BACKGROUND

International evidence suggests patients receiving cardiac interventions experience differential outcomes by their insurance status. We investigated outcomes of in-hospital care according to insurance status among patients admitted in public hospitals with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI).

METHODS

We conducted a cohort study within the Australian universal health care system with supplemental private insurance. Using linked hospital and mortality data, we included patients aged 18 + years admitted to New South Wales public hospitals with AMI and undergoing their first PCI from 2017-2020. We measured hospital-acquired complications (HACs), length of stay (LOS) and in-hospital mortality among propensity score-matched private and publicly funded patients. Matching was based on socio-demographic, clinical, admission and hospital-related factors.

RESULTS

Of 18,237 inpatients, 30.0% were privately funded. In the propensity-matched cohort (n = 10,630), private patients had lower rates of in-hospital mortality than public patients (odds ratio: 0.59, 95% CI: 0.45-0.77; approximately 11 deaths avoided per 1,000 people undergoing PCI procedures). Mortality differences were mostly driven by STEMI patients and those from major cities. There were no significant differences in rates of HACs or average LOS in private, compared to public, patients.

CONCLUSION

Our findings suggest patients undergoing PCI in Australian public hospitals with private health insurance experience lower in-hospital mortality compared with their publicly insured counterparts, but in-hospital complications are not related to patient health insurance status. Our findings are likely due to unmeasured confounding of broader patient selection, socioeconomic differences and pathways of care (e.g. access to emergency and ambulatory care; delays in treatment) that should be investigated to improve equity in health outcomes.

Chest pain epidemiology and care quality for Aboriginal and Torres Strait Islander peoples in Victoria, Australia: a population-based cohort study from 2015 to 2019

Background

This study examined chest pain epidemiology and care quality for Aboriginal and Torres Strait Islander ('Indigenous') patients presenting to hospital via emergency medical services (EMS) with chest pain.

Methods

State-wide population-based cohort study of consecutive patients attended by ambulance for acute chest pain with individual linkage to emergency, hospital admission and mortality data in the state of Victoria, Australia from January 2015 to June 2019. Multivariable models were used to assess for differences in pre-hospital and hospital adherence to care quality, process measures and clinical outcomes.

Findings

From 204,969 EMS attendances for chest pain, 3890 attendances (1.9%) identified as Aboriginal or Torres Strait Islander. Age-standardized incidence rates were higher overall for Indigenous people (3128 vs. 1147 per 100,000 person-years, incidence rate ratio 2.73, 95% CI 2.72-2.74), this difference being particularly striking for younger patients, women, and those residing in outer regional areas. In multivariable models, adherence to care quality and process measures was lower for attendances involving Indigenous people. In the pre-hospital setting, Indigenous people were less likely to be provided intravenous access or analgesia. In the hospital setting, Indigenous people were less likely to be seen by emergency clinicians within target time and less likely to transferred following myocardial infarction to a revascularization capable centre.

Interpretation

Incidence of acute chest pain presentations is high among Indigenous people in Victoria, Australia. Opportunities to improve the quality of care for Indigenous Australians presenting with acute chest pain are identified.

Funding

National Health and Medical Research Council, National Heart Foundation.

Management of Acute Coronary Syndromes in Patients in Rural Australia: The MORACS Randomized Clinical Trial

Importance

Treatment of ST-segment elevation myocardial infarction (STEMI) in rural settings involves thrombolysis followed by transfer to a percutaneous coronary intervention-capable hospital. The first step is accurate diagnosis via electrocardiography (ECG), but one-third of all STEMI incidents go unrecognized and hence untreated.

Objective

To reduce missed diagnoses of STEMI.

Design, Setting, and Participants

This cluster randomized clinical trial included 29 hospital emergency departments (EDs) in rural Australia with no emergency medicine specialists, which were randomized to usual care vs automatically triggered diagnostic support from the tertiary referral hospital (management of rural acute coronary syndromes [MORACS] intervention). Patients presenting with symptoms compatible with acute coronary syndromes (ACS) were eligible for inclusion. The study was conducted from December 2018 to April 2020. Data were analyzed in August 2021.

Intervention

Triage of a patient with symptoms compatible with ACS triggered an automated notification to the tertiary hospital coronary care unit. The ECG and point-of-care troponin results were reviewed remotely and a phone call was made to the treating physician in the rural hospital to assist with diagnosis and initiation of treatment.

Main Outcomes and Measures

The proportion of patients with missed STEMI diagnoses.

Results

A total of 6249 patients were included in the study (mean [SD] age, 63.6 [12.2] years; 48% female). Of 7474 ED presentations with suspected ACS, STEMI accounted for 77 (2.0%) in usual care hospitals and 46 (1.3%) in MORACS hospitals. Missed diagnosis of STEMI occurred in 27 of 77 presentations (35%) in usual care hospitals and 0 of 46 (0%) in MORACS hospitals (P < .001). Of eligible patients, 48 of 75 (64%) in the usual care group and 36 of 36 (100%) in the MORACS group received primary reperfusion (P < .001). In the usual care group, 12-month mortality was 10.3% (n = 8) vs 6.5% (n = 3) in the MORACS group (relative risk, 0.64; 95% CI, 0.18-2.23). Patients with missed STEMI diagnoses had a mortality of 25.9% (n = 7) compared with 2.0% (n = 1) for those with accurately diagnosed STEMI (relative risk, 13.2; 95% CI, 1.71-102.00; P = .001). Overall, there were 6 patients who did not have STEMI as a final diagnosis; 5 had takotsubo cardiomyopathy and 1 had pericarditis. There was no difference between groups in the rate of alternative final diagnosis.

Conclusion and Relevance

The findings indicate that MORACS diagnostic support service reduced the proportion of missed STEMI and improved the rates of primary reperfusion therapy. Accurate diagnosis of STEMI was associated with lower mortality.

Trial Registration

anzctr.org.au Identifier: ACTRN12619000533190.

Influence of Household Income on Management and Outcomes of Acute Myocardial Infarction Complicated by Cardiogenic Shock

The impact of socioeconomic status on care and outcomes of patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) remains understudied. Hence, adult admissions with AMI-CS were identified from the National Inpatient Sample database (2005 to 2017) and were divided into quartiles on the basis of median household income for zip code (0 to 25th, 26th to 50th, 51st to 75th, and 76th to 100th). In-hospital mortality, use of cardiac and noncardiac procedures, and resource utilization were compared between all 4 income quartiles. Among a total of 7,805,681 AMI admissions, cardiogenic shock was identified in 409,294 admissions (5.2%) with comparable prevalence of cardiogenic shock across all 4 income quartiles. AMI-CS admissions belonging to the lowest income quartile presented more often with non-ST-elevation myocardial infarction and had comparable use of coronary angiography and percutaneous coronary intervention but lower use of early coronary angiography, early percutaneous coronary intervention, mechanical circulatory support devices, and pulmonary artery catheterization than higher income quartiles. In the adjusted analysis, admissions belonging to the 0 to 25th income quartile (odds ratio [OR] 1.17 [95% confidence interval [CI] 1.15 to 1.20], p <0.001), 26th to 50th quartile (OR 1.11 [95% CI 1.09 to 1.14], p <0.001), and 51st to 75th income quartile (OR 1.06 [95% CI 1.04 to 1.09], p <0.001) had higher adjusted in-hospital mortality than the highest income quartile (76th to 100th). Lowest income quartile admissions had lower rates of palliative care consultations and higher rates of do-not-resuscitate status than the higher income quartiles. Hospitalization charges and length of stay were higher for admissions belonging to the highest income quartile. In conclusion, lowest income quartile AMI-CS admissions were associated with higher rates of non-ST-elevation myocardial infarction, lower use of mechanical circulatory support devices, and higher in-hospital mortality.

Population-Based Multilevel Models to Estimate the Management Strategies for Acute Myocardial Infarction in Older Adults with Dementia

Background

Acute myocardial infarction (AMI) management strategies, involving treatment and post-care, are much more difficult for patients with dementia. This study investigated the factors influencing the use of invasive procedures and long-term care in the management strategies for AMI patients with dementia and the factors associated with these patients' survival.

Methods

This multilevel study combined information from two databases, namely later-stage elderly healthcare insurance and long-term care insurance claims, from 2013 to 2019. Of 214,963 individuals with dementia, we identified 13,593 patients with AMI. The primary outcomes were the use of invasive procedures for treatment and long-term care for post-care management. Survival outcomes were also measured over a 6-year period, adjusting for individual- and regional-level characteristics in multilevel models.

Results

A total of 1954 (14.38%) individuals received an invasive procedure during treatment, and 7850 (87.18%) used long-term care for post-care management after AMI. After multivariate adjustment, patients aged ≥ 85 years and women were less likely to receive invasive procedures and more likely to use long-term care. Patients undergoing invasive procedures had a lower use of long-term care. Better survival outcome was significantly associated with invasive management and long-term care, regardless of the type of care.

Conclusion

Age and sex determine the use of invasive procedures and long-term care after AMI among patients with dementia. AMI patients with dementia receiving invasive procedures and long-term care had better survival outcomes.

Differences in outcome of percutaneous coronary intervention between Indigenous and non-Indigenous people in Victoria, Australia: a multicentre, prospective, observational, cohort study

BACKGROUND

Data on the patient characteristics and health outcomes of Indigenous Australians having revascularisation for treatment of coronary artery disease are scarce. The aim of this study was to assess differences in patient characteristics, presentations, and outcomes among Indigenous and non-Indigenous Australians having percutaneous coronary intervention (PCI) in urban and larger regional centres in Victoria, Australia.

METHODS

In this multicentre, prospective, observational cohort study, data were prospectively collected from six government-funded tertiary hospitals in the state of Victoria, Australia. The Melbourne Interventional Group PCI registry was used to identify patients having PCI at Victorian metropolitan and large regional hospitals between Jan 1, 2005, and Dec 31, 2018. The primary outcome was long-term mortality. Secondary outcomes were 30 day mortality and 30 day major adverse cardiovascular events (MACE), defined as a composite endpoint of death, myocardial infarction, and target-vessel revascularisation. Regression analyses, adjusted for clinically relevant covariates and geographical and socioeconomic indices, were used to establish the influence of Indigenous status on these study outcomes.

FINDINGS

41 146 patient procedures were entered into the registry, of whom 179 (0·4%) were recorded as identifying as Indigenous Australian, 39 855 (96·9%) were not Indigenous Australian, and 1112 (2·7%) had incomplete data regarding ethnicity and were excluded. Compared with their non-Indigenous counterparts, Indigenous patients were younger, more often women, and more likely to have comorbidities. Indigenous Australians were also more likely to live in a regional community and areas of socioeconomic disadvantage. Procedural success and complication rates were similar for Indigenous and non-Indigenous patients having PCI. At 30 day follow-up, Indigenous Australians were more likely to be taking optimal medical therapy, although overall follow-up rates were lower and prevalence of persistent smoking was higher. Multivariable analysis showed that Indigenous status was independently associated with increased risk of long-term mortality (hazard ratio 2·49, 95% CI 1·79-3·48; p<0·0001), 30 day mortality (odds ratio 2·78, 95% CI 1·09-7·12; p=0·033), and 30-day MACE (odds ratio 1·87, 95% CI 1·03-3·39; p=0·039).

INTERPRETATION

Indigenous Australians having PCI in urban and larger regional centres are at increased risk of mortality and adverse cardiac events. Clinically effective and culturally safe care pathways are urgently needed to improve health outcomes among Indigenous Australians who are having PCI.

FUNDING

National Health and Medical Research Council, National Heart Foundation.

Investigating inequities in cardiovascular care and outcomes for Queensland Aboriginal and Torres Strait Islander people: protocol for a hospital-based retrospective cohort data linkage project

INTRODUCTION

Cardiovascular disease (CVD) represents a significant burden of disease for Aboriginal and Torres Strait Islander people, a population that continues to experience a lower life expectancy than other Australians. The aim of the Better Cardiac Care Data Linkage project is to describe patient care pathways and to identify disparities in care and health outcomes between Aboriginal and Torres Strait Islander people and other Queensland residents diagnosed with CVD in the state of Queensland.

METHODS

This is a population-based retrospective cohort study using linked regional, state and national health and administrative data collections to describe disparities in CVD healthcare in primary and secondary prevention settings and during hospitalisation. The CVD cohort will be identified from the Queensland Hospital Admitted Patient Data Collection for admissions that occurred between 1 July 2010 and 31 June 2016 and will include relevant International Classification of Disease codes for ischaemic heart disease, congestive heart failure, stroke, acute rheumatic fever and rheumatic heart disease. Person-level data will be linked by Data Linkage Queensland and the Australian Institute of Health and Welfare (AIHW) in accordance with ethical and public health approvals to describe the patient journey prior to, during and post the hospital admission.

ANALYSIS

This project will focus largely on descriptive epidemiological measures and multivariate analysis of clinical care standards and outcomes for Aboriginal and Torres Strait Islander people compared with other Queenslanders, including identification of risk factors for suboptimal care and change over time. Variation in care pathways and patient outcomes will be compared by Indigenous status, sex, age group, remoteness of residence, year of index hospitalisation and socioeconomic status. Cox models for time-to-event data and mixed models or generalised estimating equations for longitudinal data will be used to measure change over time where temporal effects exist.

ETHICS AND DISSEMINATION

Ethical approval has been granted by Human Research Ethics Committees of the Prince Charles Hospital (HREC/15/QPCH/289) and the AIHW (EO2016-1-233). The Northern Territory Department of Health and Menzies School of Health Research have also provided reciprocal ethical approval of the project (HREC 2019-3490). The deidentified results will be summarised in a report and shared with investigators, advisory groups, Queensland Health and key stakeholders. Findings will be disseminated through workshops, conferences and will be published in peer-reviewed journals.

Cardiac procedures in ST-segment-elevation myocardial infarction - the influence of age, geography and Aboriginality

Background

Timely restoration of bloodflow acute ST-segment elevation myocardial infarction (STEMI) reduces myocardial damage and improves prognosis. The objective of this study was describe the association of demographic factors with hospitalisation rates for STEMI and time to angiography, Percutaneous Coronary Intervention (PCI) and Coronary Artery Bypass Graft (CABG) in New South Wales (NSW) and the Australian Capital Territory (ACT), Australia.

Methods

This was an observational cohort study using linked population health data. We used linked records of NSW and the ACT hospitalisations and the Australian Government Medicare Benefits Schedule (MBS) for persons aged 35 and over hospitalised with STEMI in the period 1 July 2010 to 30 June 2014. Survival analysis was used to determine the time between STEMI admission and angiography, PCI and CABG, with a competing risk of death without cardiac procedure.

Results

Of 13,117 STEMI hospitalisations, 71% were among males; 55% were 65-plus years; 64% lived in major cities, and 2.6% were Aboriginal people. STEMI hospitalisation occurred at a younger age in males than females. Angiography and PCI rates decreased with age: angiography 69% vs 42% and PCI 60% vs 34% on day 0 for ages 35-44 and 75-plus respectively. Lower angiography and PCI rates and higher CABG rates were observed outside major cities. Aboriginal people with STEMI were younger and more likely to live outside a major city. Angiography, PCI and CABG rates were similar for Aboriginal and non-Aboriginal people of the same age and remoteness area.

Conclusions

There is a need to improve access to definitive revascularisation for STEMI among appropriately selected older patients and in regional areas. Aboriginal people with STEMI, as a population, are disproportionately affected by access to definitive revascularisation outside major cities. Improving access to timely definitive revascularisation in regional areas may assist in closing the gap in cardiovascular outcomes between Aboriginal and non-Aboriginal people.

Neutrophil-Derived S100A8/A9 Amplify Granulopoiesis After Myocardial Infarction

BACKGROUND

Myocardial infarction (MI) triggers myelopoiesis, resulting in heightened production of neutrophils. However, the mechanisms that sustain their production and recruitment to the injured heart are unclear.

METHODS

Using a mouse model of the permanent ligation of the left anterior descending artery and flow cytometry, we first characterized the temporal and spatial effects of MI on different myeloid cell types. We next performed global transcriptome analysis of different cardiac cell types within the infarct to identify the drivers of the acute inflammatory response and the underlying signaling pathways. Using a combination of genetic and pharmacological strategies, we identified the sequelae of events that led to MI-induced myelopoiesis. Cardiac function was assessed by echocardiography. The association of early indexes of neutrophilia with major adverse cardiovascular events was studied in a cohort of patients with acute MI.

RESULTS

Induction of MI results in rapid recruitment of neutrophils to the infarct, where they release specific alarmins, S100A8 and S100A9. These alarmins bind to the Toll-like receptor 4 and prime the nod-like receptor family pyrin domain-containing 3 inflammasome in naïve neutrophils and promote interleukin-1β secretion. The released interleukin-1β interacts with its receptor (interleukin 1 receptor type 1) on hematopoietic stem and progenitor cells in the bone marrow and stimulates granulopoiesis in a cell-autonomous manner. Genetic or pharmacological strategies aimed at disruption of S100A8/A9 and their downstream signaling cascade suppress MI-induced granulopoiesis and improve cardiac function. Furthermore, in patients with acute coronary syndrome, higher neutrophil count on admission and after revascularization correlates positively with major adverse cardiovascular disease outcomes.

CONCLUSIONS

Our study provides novel evidence for the primary role of neutrophil-derived alarmins (S100A8/A9) in dictating the nature of the ensuing inflammatory response after myocardial injury. Therapeutic strategies aimed at disruption of S100A8/A9 signaling or their downstream mediators (eg, nod-like receptor family pyrin domain-containing 3 inflammasome, interleukin-1β) in neutrophils suppress granulopoiesis and may improve cardiac function in patients with acute coronary syndrome.

Multimorbidity among Aboriginal people in New South Wales contributes significantly to their higher mortality

OBJECTIVES

To compare the prevalence of multimorbidity and its impact on mortality among Aboriginal and non-Aboriginal Australians who had been hospitalised in New South Wales in the previous 10 years.

DESIGN, SETTING AND PARTICIPANTS

Cohort study analysis of linked NSW hospital (Admitted Patient Data Collection) and mortality data for 5 437 018 New South Wales residents with an admission to a NSW hospital between 1 March 2003 and 1 March 2013, and alive at 1 March 2013.

MAIN OUTCOME MEASURES

Admissions for 30 morbidities during the 10-year study period were identified. The primary outcome was the presence or absence of multimorbidity during the 10-year lookback period; the secondary outcome was mortality in the 12 months from 1 March 2013 to 1 March 2014.

RESULTS

31.5% of Aboriginal patients had at least one morbidity and 16.1% had two or more, compared with 25.0% and 12.1% of non-Aboriginal patients. After adjusting for age, sex, and socio-economic status, the prevalence of multimorbidity among Aboriginal people was 2.59 times that for non-Aboriginal people (95% CI, 2.55-2.62). The prevalence of multimorbidity was higher among Aboriginal people in all age groups, in younger age groups because of the higher prevalence of mental morbidities, and from age 60 because of physical morbidities. The age-, sex- and socio-economic status-adjusted hazard of one-year mortality (Aboriginal v non-Aboriginal Australians) was 2.43 (95% CI, 2.24-2.62), and 1.51 (95% CI, 1.39-1.63) after also adjusting for morbidity count.

CONCLUSIONS

The prevalence of multimorbidity was higher among Aboriginal than non-Aboriginal patients, and this difference accounted for much of the difference in mortality between the two groups. Evidence-based interventions for reducing multimorbidity among Aboriginal and Torres Strait Islander Australians must be a priority.

A Review of Coronary Artery Bypass Grafting in the Indigenous Australian Population

INTRODUCTION

Indigenous Australians experience poorer health outcomes than non-Indigenous Australians. Ischaemic heart disease is a leading contributor to the mortality gap which exists between Indigenous and non-Indigenous Australians.

METHODS

We reviewed the literature in regards to Indigenous Australians undergoing coronary artery bypass grafting (CABG) for management of ischaemic heart disease.

RESULTS

Younger patients with higher rates of preventable risk factors constitute the Indigenous Australian CABG population. Indigenous Australian females are over-represented in series to date. High rates of left ventricular dysfunction are seen in the Indigenous CABG cohorts potentially reflecting barriers to medical care or the influence of high rates of diabetes observed in the Indigenous Australian population. The distribution of coronary artery disease appears to differ between Indigenous Australian and non-Indigenous CABG cohorts likely reflecting a difference in the referral patterns of the two population groups with diabetes again likely influencing management decisions. Reduced utilisation of arterial conduits in Indigenous Australian cohorts has been identified in a number of series. This is of particular concern given the younger age structure of the Indigenous Australian cohorts. Indigenous Australian patients suffer excess morbidity and mortality in the longer term after undergoing CABG. Ventricular dysfunction and excess comorbidities in the Indigenous Australian CABG population appear largely responsible for this.

CONCLUSION

Excess morbidity and mortality endured by Indigenous Australians in the longer term following CABG appears largely contributed to by higher rates of ventricular dysfunction and comorbidities in the Indigenous Australian CABG population. Maximising internal mammary artery use and continued focus on strategies to reduce the impact of diabetes, renal impairment and heart failure in the Indigenous Australian population is essential to reduce the mortality gap experienced by Indigenous Australians secondary to ischaemic heart disease.

Comorbidities and Ventricular Dysfunction Drive Excess Mid-Term Morbidity in an Indigenous Australian Coronary Revascularisation Cohort

BACKGROUND

There is a paucity of data in regards to longer term morbidity outcomes in Indigenous Australian patients undergoing coronary artery bypass grafting (CABG). No comparative data on re-infarction, stroke or reintervention rates exist. Outcome data following percutaneous coronary intervention (PCI) is also extremely limited. Addressing this gap in knowledge forms the major aim of our study.

METHODS

This was a single centre cohort study conducted at the Townsville Hospital, Australia which provides tertiary adult cardiac surgical services to the northern parts of the state of Queensland. It incorporated consecutive patients (n=350) undergoing isolated CABG procedures, 2008-2010, 20.9% (73/350) of whom were Indigenous Australians. The main outcome measures were major adverse cardiac or cerebrovascular events (MACCE) at mid-term follow-up (mean 38.9 months).

RESULTS

The incidence of MACCE among Indigenous Australian patients was approximately twice that of non-Indigenous patients at mid-term follow-up (36.7% vs. 18.6%; p=0.005; OR 2.525 (1.291-4.880)). Following adjustment for preoperative and operative variables, Indigenous Australian status itself was not significantly associated with MACCE (AOR 1.578 (0.637-3.910)). Significant associations with MACCE included renal impairment (AOR 2.198 (1.010-4.783)) and moderate-severe left ventricular impairment (AOR 3.697 (1.820-7.508)). An association between diabetes and MACCE failed to reach statistical significance (AOR 1.812 (0.941-3.490)).

CONCLUSIONS

Indigenous Australians undergoing CABG suffer an excess of MACCE when followed-up in the longer term. High rates of comorbidities in the Indigenous Australian population likely play an aetiological role.

An Overview of Indigenous Australian Disadvantage in Terms of Ischaemic Heart Disease

BACKGROUND

Indigenous Australians experience poorer health outcomes than non-Indigenous Australians and a significant life expectancy gap exists. Ischaemic heart disease (IHD) represents the leading specific cause of death in Indigenous Australians and is a significant, if not the most significant, contributor to the mortality gap. With this narrative review we aim to describe the burden of IHD within the Indigenous Australian community and explore the factors driving this disparity.

METHODS

A broad search of the literature was undertaken utilising an electronic search of the PubMed database along with national agency databases-the Australian Institute of Health and Welfare (AIHW) and the Australian Bureau of Statistics (ABS).

RESULTS

A complex interplay between multiple factors contributes to the excess burden of IHD in the Indigenous Australian population: CONCLUSIONS: In terms of IHD, Indigenous Australians experience disadvantage at multiple stages of the disease process. Ongoing efforts are needed to continue to inform clinicians of both this disadvantage and strategies to assist negating it. Further research is needed to develop evidence based practices which may help reduce this disparity in outcomes.

Exploring Aboriginal patients' experiences of cardiac care at a major metropolitan hospital in Melbourne

Objectives The aim of the present study was to explore Aboriginal patients' lived experiences of cardiac care at a major metropolitan hospital in Melbourne. Methods The study was a qualitative study involving in-depth interviews with a purposive sample of 10 Aboriginal patients who had been treated in the cardiology unit at the study hospital during 2012-13. A phenomenological approach was used to analyse the data. Results Eight themes emerged from the data, each concerning various aspects of participants' experiences: 'dislike of hospitals', 'system failures', 'engagement with hospital staff', 'experiences of racism', 'health literacy and information needs', 'self-identifying as Aboriginal', 'family involvement in care' and 'going home and difficulties adapting'. Most participants had positive experiences of the cardiac care, but hospitalisation was often challenging because of a sense of dislocation and disorientation. The stress of hospitalisation was greatly mediated by positive engagements with staff, but at times exacerbated by system failures or negative experiences. Conclusion Cardiac crises are stressful and hospital stays were particularly disorienting for Aboriginal people dislocated from their home land and community. What is known about the topic? Aboriginal people have higher mortality rates due to cardiovascular diseases compared with other Australians. Along with different factors contributing to the life expectancy gap, Aboriginal people also face significant barriers in the use of the healthcare system. What does this paper add? Aboriginal patients' lived experience of cardiac care at a major metropolitan hospital in Melbourne is explored in this paper. Different issues were revealed during their interaction with the hospital staff and the hospital system in conjunction with their cultural aspect of patient care. What are the implications for practitioners? Positive interactions with staff, ongoing support from family and community, culturally appropriate cardiac rehabilitation programs can improve the cardiac care experiences of Aboriginal patients.

Disparities experienced by Aboriginal compared to non-Aboriginal metropolitan Western Australians in receiving coronary angiography following acute ischaemic heart disease: the impact of age and comorbidities

INTRODUCTION

Aboriginal Australians have a substantially higher frequency of ischaemic heart disease (IHD) events than their non-Aboriginal counterparts, together with a higher prevalence of comorbidities. The pattern of health service provision for IHD suggests inequitable delivery of important diagnostic procedures. Published data on disparities in IHD management among Aboriginal Australians are conflicting, and the role of comorbidities has not been adequately delineated. We compared the profiles of Aboriginal and non-Aboriginal patients in the metropolitan area undergoing emergency IHD admissions at Western Australian metropolitan hospitals, and investigated the determinants of receiving coronary angiography.

METHODS

Person-linked administrative hospital and mortality records were used to identify 28-day survivors of IHD emergency admission events (n =20,816) commencing at metropolitan hospitals in 2005-09. The outcome measure was receipt of angiography. The Aboriginal to non-Aboriginal risk ratio (RR) was estimated from a multivariable Poisson log-linear regression model with allowance for multiple IHD events in individuals. The subgroup of myocardial infarction (MI) events was modelled separately.

RESULTS

Compared with their non-Aboriginal counterparts, Aboriginal IHD patients were younger and more likely to have comorbidities. In the age- and sex-adjusted model, Aboriginal patients were less likely than others to receive angiography (RRIHD 0.77, 95% CI 0.72-0.83; RRMI 0.81, 95% CI 0.75-0.87) but in the full multivariable model this disparity was accounted for by comorbidities as well as IHD category and MI subtype, and private health insurance (RRIHD 0.95, 95% CI 0.89-1.01; RRMI 0.94, 95% CI 0.88-1.01). When stratified by age groups, this disparity was not significant in the 25-54 year age group (RRMI 0.95, 95% CI 0.88-1.02) but was significant in the 55-84 year age group (RRMI 0.88, 95% CI 0.77-0.99).

CONCLUSIONS

The disproportionate under-management of older Aboriginal IHD patients is of particular concern. Regardless of age, the disparity between Aboriginal and non-Aboriginal Australians in receiving angiography for acute IHD in a metropolitan setting is mediated substantially by comorbidities. This constellation of health problems is a 'double-whammy' for Aboriginal people, predisposing them to IHD and also adversely impacting on their receipt of angiography. Further research should investigate how older age and comorbidities influence clinical decision making in this context.

Variation in the recording of common health conditions in routine hospital data: study using linked survey and administrative data in New South Wales, Australia

OBJECTIVES

To investigate the nature and potential implications of under-reporting of morbidity information in administrative hospital data.

SETTING AND PARTICIPANTS

Retrospective analysis of linked self-report and administrative hospital data for 32,832 participants in the large-scale cohort study (45 and Up Study), who joined the study from 2006 to 2009 and who were admitted to 313 hospitals in New South Wales, Australia, for at least an overnight stay, up to a year prior to study entry.

OUTCOME MEASURES

Agreement between self-report and recording of six morbidities in administrative hospital data, and between-hospital variation and predictors of positive agreement between the two data sources.

RESULTS

Agreement between data sources was good for diabetes (κ=0.79); moderate for smoking (κ=0.59); fair for heart disease, stroke and hypertension (κ=0.40, κ=0.30 and κ =0.24, respectively); and poor for obesity (κ=0.09), indicating that a large number of individuals with self-reported morbidities did not have a corresponding diagnosis coded in their hospital records. Significant between-hospital variation was found (ranging from 8% of unexplained variation for diabetes to 22% for heart disease), with higher agreement in public and large hospitals, and hospitals with greater depth of coding.

CONCLUSIONS

The recording of six common health conditions in administrative hospital data is highly variable, and for some conditions, very poor. To support more valid performance comparisons, it is important to stratify or control for factors that predict the completeness of recording, including hospital depth of coding and hospital type (public/private), and to increase efforts to standardise recording across hospitals. Studies using these conditions for risk adjustment should also be cautious of their use in smaller hospitals.

Transfers to metropolitan hospitals and coronary angiography for rural Aboriginal and non-Aboriginal patients with acute ischaemic heart disease in Western Australia

Background

Aboriginal people have a disproportionately higher incidence rate of ischaemic heart disease (IHD) than non-Aboriginal people. The findings on Aboriginal disparity in receiving coronary artery procedures are inconclusive. We describe the profile and transfers of IHD patients admitted to rural hospitals as emergency admissions and investigate determinants of transfers and coronary angiography.

Methods

Person-linked hospital and mortality records were used to identify 28-day survivors of IHD events commencing at rural hospitals in Western Australia. Outcome measures were receipt of coronary angiography, transfer to a metropolitan hospital, and coronary angiography if transferred to a metropolitan hospital.

Results

Compared to non-Aboriginal patients, Aboriginal patients with IHD were more likely to be younger, have more co-morbidities, reside remotely, but less likely to have private insurance. After adjusting for demographic characteristics, Aboriginal people with MI were less likely to be transferred to a metropolitan hospital, and if transferred were less likely to receive coronary angiography. These disparities were not significant after adjusting for comorbidities and private insurance. In the full multivariate model age, comorbidities and private insurance were adversely associated with transfer to a metropolitan hospital and coronary angiography.

Conclusion

Disparity in receiving coronary angiography following emergency admission for IHD to rural hospitals is mediated through the lower likelihood of being transferred to metropolitan hospitals where this procedure is performed. The likelihood of a transfer is increased if the patient has private insurance, however, rural Aboriginal people have a lower rate of private insurance than their non-Aboriginal counterparts. Health practitioners and policy makers can continue to claim that they treat Aboriginal and non-Aboriginal people alike based upon clinical indications, as private insurance is acting as a filter to reduce rural residents accessing interventional cardiology. If health practitioners and policy makers are truly committed to reducing health disparities, they must reflect upon the broader systems in which disparity is perpetuated and work towards a systems improvement.

Risk adjustment for smoking identified through tobacco use diagnoses in hospital data: a validation study

Adjustment for the differing risk profiles of patients is essential to the use of administrative hospital data for epidemiological research. Smoking is an important factor to include in such adjustments, but the accuracy of the diagnostic codes denoting smoking in hospital records is unknown. The aims of this study were to measure the validity of current smoking and ever smoked status identified from diagnoses in hospital records using a range of algorithms, relative to self-reported smoking status; and to examine whether the misclassification of smoking identified through hospital data is differential or non-differential with respect to common exposures and outcomes. Data from the baseline questionnaire of the 45 and Up Study, completed by 267,153 residents of New South Wales (NSW), Australia, aged 45 years and older, were linked to the NSW Admitted Patient Data Collection. Patients who had been admitted to hospital for an overnight stay between 1 July 2005 and the date of completion of the questionnaire (1 January 2006 to 2 March 2009) were included. Smokers were identified by applying a range of algorithms to hospital admission histories, and compared against self-reported smoking in the questionnaire (‘gold standard’). Sensitivities for current smoking ranged from 59% to 84%, while specificities were 94% to 98%. Sensitivities for ever smoked ranged from 45% to 74% and specificities were 93% to 97%. For the majority of algorithms, sensitivities and/or specificities differed significantly according to principal diagnosis, number of comorbidities, socioeconomic status, residential remoteness, Indigenous status, 28 day readmission and 365 day mortality. The identification of smoking through diagnoses in hospital data results in differential misclassification. Risk adjustment based on smoking identified from these data will yield potentially misleading results. Systematic capture of information about smoking in hospital records using a mandatory item would increase the utility of administrative data for epidemiological research.

Implementing guideline based heart failure care in the Northern Territory: challenges and solutions

The Northern Territory of Australia is a vast area serviced by two major tertiary hospitals. It has both a unique demography and geography, which pose challenges for delivering optimal heart failure services. The prevalence of congestive heart failure continues to increase, imposing a significant burden on health infrastructure and health care costs. Specific patient groups suffer disproportionately from increased disease severity or service related issues often represented as a "health care gap". The syndrome itself is characterised by ongoing symptoms interspersed with acute decompensation requiring lifelong therapy and is rarely reversible. For the individual client the overwhelming attention to heart failure care and the impact of health care gaps can be devastating. This gap may also contribute to widening socio-economic differentials for families and communities as they seek to take on some of the care responsibilities. This review explores the challenges of heart failure best practice in the Northern Territory and the opportunities to improve on service delivery. The discussions highlighted could have implications for health service delivery throughout regional centres in Australia and health systems in other countries.