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

Low-level elevations in high-sensitivity cardiac troponin predict obstructive coronary artery disease and revascularisation in rural patients with non-ST-elevation myocardial infarction referred for coronary angiography

Rural patients with non-ST-elevation myocardial infarction (NSTEMI) are transferred to metropolitan hospitals for invasive coronary angiography (ICA). Yet, many do not have obstructive coronary artery disease (CAD). In this analysis of rural Western Australian patients transferred for ICA for NSTEMI, low-level elevations in high-sensitivity cardiac troponin (≤5× upper reference limit) were associated with less obstructive CAD and revascularisation. Along with other factors, this may help identify rural patients not requiring transfer for ICA.

Avoiding double counting: the effect of bundling hospital events in administrative datasets for the interpretation of rural-urban differences in Aotearoa New Zealand

BACKGROUND AND OBJECTIVES

All publicly funded hospital discharges in Aotearoa New Zealand are recorded in the National Minimum Dataset (NMDS). Movement of patients between hospitals (and occasionally within the same hospital) results in separate records (discharge events) within the NMDS and if these consecutive health records are not accounted for hospitalization (encounters) rates might be overestimated. The aim of this study was to determine the impact of four different methods to bundle multiple discharge events in the NMDS into encounters on the relative comparison of rural and urban Ambulatory Sensitive Hospitalization (ASH) rates.

METHODS

NMDS discharge events with an admission date between July 1, 2015, and December 31, 2019, were bundled into encounters using either using a) no method, b) an "admission flag", c) a "discharge flag", or d) a date-based method. ASH incidence rate ratios (IRRs), the mean total length of stay and the percentage of interhospital transfers were estimated for each bundling method. These outcomes were compared across 4 categories of the Geographic Classification for Health.

RESULTS

Compared with no bundling, using the date-based method resulted in an 8.3% reduction (150 less hospitalizations per 100,000 person years) in the estimated incidence rate for ASH in the most rural (R2-3) regions. There was no difference in the interpretation of the rural-urban IRR for any bundling methodology. Length of stay was longer for all bundling methods used. For patients that live in the most rural regions, using a date-based method identified up to twice as many interhospital transfers (5.7% vs 12.4%) compared to using admission flags.

CONCLUSION

Consecutive events within hospital discharge datasets should be bundled into encounters to estimate incidence. This reduces the overestimation of incidence rates and the undercounting of interhospital transfers and total length of stay.

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.

Clinical outcomes and health care costs of transferring rural Western Australians for invasive coronary angiography, and a cost-effective alternative care model: a retrospective cross-sectional study

OBJECTIVES

To examine the severity of coronary artery disease (CAD) in people from rural or remote Western Australia referred for invasive coronary angiography (ICA) in Perth and their subsequent management; to estimate the cost savings were computed tomography coronary angiography (CTCA) offered in rural centres as a first line investigation for people with suspected CAD.

DESIGN

Retrospective cohort study.

SETTING, PARTICIPANTS

Adults with stable symptoms in rural and remote WA referred to Perth public tertiary hospitals for ICA evaluation during the 2019 calendar year.

MAIN OUTCOME MEASURES

Severity and management of CAD (medical management or revascularisation); health care costs by care model (standard care or a proposed alternative model with local CTCA assessment).

RESULTS

The mean age of the 1017 people from rural and remote WA who underwent ICA in Perth was 62 years (standard deviation, 13 years); 680 were men (66.9%), 245 were Indigenous people (24.1%). Indications for referral were non-ST elevation myocardial infarction (438, 43.1%), chest pain with normal troponin level (394, 38.7%), and other (185, 18.2%). After ICA assessment, 619 people were medically managed (60.9%) and 398 underwent revascularisation (39.1%). None of the 365 patients (35.9%) without obstructed coronaries (< 50% stenosis) underwent revascularisation; nine patients with moderate CAD (50-69% stenosis; 7%) and 389 with severe CAD (≥ 70% stenosis or occluded vessel; 75.5%) underwent revascularisation. Were CTCA used locally to determine the need for referral, 527 referrals could have been averted (53%), the ICA:revascularisation ratio would have improved from 2.6 to 1.6, and 1757 metropolitan hospital bed-days (43% reduction) and $7.3 million in health care costs (36% reduction) would have been saved.

CONCLUSION

Many rural and remote Western Australians transferred for ICA in Perth have non-obstructive CAD and are medically managed. Providing CTCA as a first line investigation in rural centres could avert half of these transfers and be a cost-effective strategy for risk stratification of people with suspected CAD.

The Hospital Frailty Risk Score Identifies Fewer Cases of Frailty in a Community-Based Cohort of Older Men Than the FRAIL Scale and Frailty Index

OBJECTIVES

The recently developed Hospital Frailty Risk Score (HFRS) allows ascertainment of frailty from administrative data. We aimed to compare the HFRS against the widely used FRAIL Scale and Frailty Index.

DESIGN

Population-based cohort study linked to Western Australian Hospital Morbidity Data Collection and Death Registrations.

SETTING AND PARTICIPANTS

The Health in Men Study with frailty determined at Wave 2 (2001/2004), mortality in the 1-year period following Wave 2, and disability at Wave 3 (2008). Participants were 4228 community-based men aged ≥75 years, followed until Wave 3.

MEASUREMENTS

We used multivariable regression to determine the association between each frailty measure and outcomes of length of stay (LOS), death, and disability. We also determined if the additional cases of frailty identified by one measure over the other was associated with these outcomes.

RESULTS

Of 4228 men studied, the HFRS (n = 689) identified fewer men as frail than the FRAIL Scale (n = 1648) and Frailty Index (n = 1820). In the fully adjusted models, all 3 frailty measures were associated with longer LOS and mortality, whereas only the FRAIL Scale and Frailty Index were significantly associated with disability. The additional cases of frailty identified by the FRAIL Scale and Frailty Index had longer LOS and greater risks of death and disability. The fully adjusted hazard ratio for death among the additional cases of frailty identified by the FRAIL Scale (compared to being not frail on both HFRS and FRAIL Scale) was 2.14 (95% CI 1.48-3.08).

CONCLUSIONS AND IMPLICATIONS

The HFRS is associated with adverse outcomes. However, it identified approximately 60% fewer men who were frail than the FRAIL Scale and Frailty Index, and the additional cases identified were also at high risks of adverse outcomes. Users of the HFRS should be aware of the differences with other frailty measures.

Effect of frailty on initiation of statins following incident acute coronary syndromes in patients aged ≥75 years

INTRODUCTION

Statin use for preventing recurrent acute coronary syndromes (ACS) is low in older people due to many clinical factors, including frailty. Using the recently developed hospital frailty risk score, which allows ascertainment of frailty from real-world data, we examined the association between frailty and initiation of statin treatment following incident ACS in patients aged ≥75 years. Our secondary aim was to determine whether non-initiation of statins was associated with more conservative treatment, defined as non-receipt of evidence-based medicines and/or coronary artery procedures.

METHODS

We used person-linked hospital administrative and Pharmaceutical Benefits Scheme data to identify incident ACS admissions between 2005 and 2008 in Western Australia and prescription medicine use, respectively. Outcomes were receipt of any statin, high-dose statin, beta-blockers, renin-angiotensin system inhibitors (RASI), antiplatelets and coronary artery procedures within six months of the incident ACS and were analysed using multivariable generalised linear regression models.

RESULTS

In 1,558 patients (52.4% female, mean age 82.6 years), initiation of any statin or high-dose statin decreased with increasing frailty. The adjusted risk ratios for any statin were 0.89 (95% CI: 0.82-0.97) and 0.67 (95% CI: 0.54-0.85) for the intermediate- and high-frailty categories compared with the low-frailty category, respectively. Compared with patients who received statins, those not receiving statins were less likely (p<0.001) to receive beta-blockers (80.8% vs 51.5%), RASI (86.9% vs 62.1%), antiplatelets (90.9% vs 65.1%) or a coronary artery procedure (65.9% vs 21.1%).

CONCLUSIONS

Increasing frailty is inversely associated with initiation of statins and generally leads to a more conservative approach to treatment of older patients with ACS.

Frailty, and not medicines with anticholinergic or sedative effects, predicts adverse outcomes in octogenarians admitted for myocardial infarction: Population-level study

OBJECTIVE

To determine independent associations between the use of medicines with anticholinergic or sedative effects and frailty with outcomes of length of stay (LOS), coronary artery procedure performed and 30-day deaths in octogenarians admitted for a myocardial infarction (MI).

METHODS

We quantified patient exposure to medicines with anticholinergic or sedative effects using the drug burden index (DBI) and frailty using the hospital frailty risk score (HFRS). We used multivariable regression methods to determine the association between DBI and HFRS with outcomes of LOS, coronary artery procedures performed and 30-day deaths.

RESULTS

HFRS and not DBI score was significantly associated with receipt of coronary artery procedures (odds ratio [OR] 0.42; 95% CI 0.28-0.62 for high- versus low-risk groups) and 30-day deaths (OR 1.58; 95% CI 1.12-2.24 for high- versus low-risk groups).

CONCLUSION

Frailty risk is a more important predictor of outcomes than DBI score for octogenarians with an MI.

Exploring the experiences of Aboriginal and Torres Strait Islander patients admitted to a metropolitan health service

Objective There continue to be disparate health outcomes for people who are Aboriginal and Torres Strait Islander. The aim of the present study was to measure whether there were any differences in in-patient experiences between Aboriginal and Torres Strait Islander people and those without an Aboriginal or Torres Strait Islander background. Methods Random samples of people were invited to complete a survey following admission at the hospitals at Peninsula Health, Victoria, Australia. This survey was based on the Victorian Patient Satisfaction Monitor. Open-ended questions were also asked to gauge perspectives on how the services could better meet needs of Aboriginal and Torres Strait Islander patients. Results A total of 154 responses was obtained. There were differences between the two groups of participants in the following variables: respect of privacy, representation of culture, assistance with meals and access to a culturally specific worker if needed. This was reflected in thematic analysis, with three main themes identified: (1) interactions with staff; (2) the challenging environment; and (3) not just about me, but my family too. Conclusion There were systemic differences in in-patient experiences. Healthcare services have a responsibility to make systemic changes to improve the health care of all Australians by understanding and reforming how services can be appropriately delivered. What is known about the topic? There is a disparity in health outcomes between Aboriginal and Torres Strait Islander Australians and those who do not identify as Aboriginal and/or Torres Strait Islander. In addition, Aboriginal and Torres Strait Islanders have different interactions within healthcare services. Many rural health services have models that aim to deliver culturally appropriate services, but it is unknown whether the same challenges apply for this group of Australians within metropolitan health services. What does this paper add? This paper identifies the structural supports that are required to help close the gap in health care provision inequality. Many of the key issues identified are not people but system based. Healthcare administrators should consider the factors identified and address these at a whole-of-service level. What are the implications for practitioners? Many practitioners are aware of the challenges of providing culturally appropriate services. This research raises awareness of how traditional healthcare is not a one size fits all and flexibility is required to improve health 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.

Exploring the effects of transfers and readmissions on trends in population counts of hospital admissions for coronary heart disease: a Western Australian data linkage study

OBJECTIVES

To develop a method for categorising coronary heart disease (CHD) subtype in linked data accounting for different CHD diagnoses across records, and to compare hospital admission numbers and ratios of unlinked versus linked data for each CHD subtype over time, and across age groups and sex.

DESIGN

Cohort study.

DATA SOURCE

Person-linked hospital administrative data covering all admissions for CHD in Western Australia from 1988 to 2013.

MAIN OUTCOME

Ratios of (1) unlinked admission counts to contiguous admission (CA) counts (accounting for transfers), and (2) 28-day episode counts (accounting for transfers and readmissions) to CA counts stratified by CHD subtype, sex and age group.

RESULTS

In all CHD subtypes, the ratios changed in a linear or quadratic fashion over time and the coefficients of the trend term differed across CHD subtypes. Furthermore, for many CHD subtypes the ratios also differed by age group and sex. For example, in women aged 35-54 years, the ratio of unlinked to CA counts for non-ST elevation myocardial infarction admissions in 2000 was 1.10, and this increased in a linear fashion to 1.30 in 2013, representing an annual increase of 0.0148.

CONCLUSION

The use of unlinked counts in epidemiological estimates of CHD hospitalisations overestimates CHD counts. The CA and 28-day episode counts are more aligned with epidemiological studies of CHD. The degree of overestimation of counts using only unlinked counts varies in a complex manner with CHD subtype, time, sex and age group, and it is not possible to apply a simple correction factor to counts obtained from unlinked data.

Improving cardiovascular outcomes among Aboriginal Australians: Lessons from research for primary care

BACKGROUND

The Aboriginal people of Australia have much poorer health and social indicators and a substantial life expectancy gap compared to other Australians, with premature cardiovascular disease a major contributor to poorer health. This article draws on research undertaken to examine cardiovascular disparities and focuses on ways in which primary care practitioners can contribute to reducing cardiovascular disparities and improving Aboriginal health.

METHODS

The overall research utilised mixed methods and included data analysis, interviews and group processes which included Aboriginal people, service providers and policymakers. Workshop discussions to identify barriers and what works were recorded by notes and on whiteboards, then distilled and circulated to participants and other stakeholders to refine and validate information. Additional engagement occurred through circulation of draft material and further discussions. This report distils the lessons for primary care practitioners to improve outcomes through management that is attentive to the needs of Aboriginal people.

RESULTS

Aspects of primordial, primary and secondary prevention are identified, with practical strategies for intervention summarised. The premature onset and high incidence of Aboriginal cardiovascular disease make prevention imperative and require that primary care practitioners understand and work to address the social underpinnings of poor health. Doctors are well placed to reinforce the importance of healthy lifestyle at all visits to involve the family and to reduce barriers which impede early care seeking. Ensuring better information for Aboriginal patients and better integrated care for patients who frequently have complex needs and multi-morbidities will also improve care outcomes.

CONCLUSION

Primary care practitioners have an important role in improving Aboriginal cardiovascular care outcomes. It is essential that they recognise the special needs of their Aboriginal patients and work at multiple levels both outside and inside the clinic for prevention and management of disease. A toolkit of proactive and holistic opportunities for interventions is proposed.

Effects of health service geographic accessibility in patients with treated end stage kidney disease: Cohort study 2000-2010

AIM

Patients in rural areas experience poor access to health services. There are limited data on patterns of health service utilization in rural patients treated with renal replacement therapy (RRT).

METHODS

All prevalent patients over the age of 18 and resident in New South Wales who were receiving RRT on 01/07/2000 and incident patients who started RRT between 01/07/2000 up until 31/07/2010 were included in the study. The Accessibility Remoteness Index of Australia was used to measure rurality and to categorize participant postcode of residence at the time of their first use of a New South Wales healthcare facility after the start of RRT. We assessed (1) rates of hospitalization, (2) rates of inter-hospital transfer (IHT), (3) length of hospital stay (LOS) and (4) survival. Day-only and dialysis admissions were excluded. Negative binomial regression was used to calculate incidence rate ratios (IRR) for hospitalizations, IHT and LOS. Cox proportional hazards was used to calculate hazard ratios (HR) for survival.

RESULTS

Of the 10 505 patients included in the analysis, 1527 (15%) were rural residents while 8978 (85%) resided in urban areas. Median follow up time from start of RRT/study to end of study/death was 4.2 years (IQR 2.0 to 8.2). After allowing for differences in baseline characteristics, rural residence increased the rates of hospitalization by 8% (IRR 1.08: 95% CI 1.01-1.15; P = 0.02), rates of IHT by 176% (IRR 2.76: 95% CI 2.44-3.13; P < 0.001) and the hazard of death by 14% (HR 1.14 95% CI: 1.05-1.24; P = 0.003) LOS was similar (Median 4.0; P = 0.07).

CONCLUSIONS

Rural residents receiving RRT have higher hospitalization rates, markedly higher rates of IHT and higher long-term mortality compared with their urban counterparts.

Is the incidence of heart attack still decreasing in Australia? Developing reliable methods for monitoring trends in myocardial infarction and coronary heart disease (AUS-MOCHA): a study protocol

INTRODUCTION

Accurate monitoring of acute coronary heart disease (CHD) is essential for understanding the effects of primary and secondary prevention and for planning of healthcare services. The ability to reliably monitor acute CHD has been affected by new diagnostic tests for myocardial infarction (MI) and changing clinical classifications and management of CHD. Our study will develop new and reliable methods for monitoring population trends in incidence, outcomes and health service usage for acute CHD and chest pain.

METHODS AND ANALYSIS

The study cohort of all CHD will be identified from the Western Australian Data Linkage System using state-wide data sets for emergency department presentation, hospitalisations and mortality data for 2002-2014. This core linked data set will be supplemented with data from hospital medical record reviews, pathology data and hospital pharmacy dispensing databases. The consistency over time of the coding of the different subgroups of CHD/chest pain (ST-elevation MI, non-ST elevation MI, unstable angina, stable angina, other CHD, non-CHD chest pain) in linked data will be assessed using these data sources, and an algorithm developed detailing groups in which temporal trends can be reliably measured. This algorithm will be used for measurement of trends in incidence and outcomes of acute CHD, and to develop further methods for monitoring acute CHD using unlinked and linked data with varying availability of hospitalisation history.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the Human Research Ethics Committees of the WA Department of Health (#2016/23) and The University of Western Australia (RA/4/1/7230). Findings will be disseminated via publication in peer-reviewed journals, and presentation at national and international conferences. There will also be a strong platform for dissemination of new monitoring methods via collaboration with the Australian Institute of Health and Welfare which will assist with promotion of these methods at state and national levels.

Knowledge translation lessons from an audit of Aboriginal Australians with acute coronary syndrome presenting to a regional hospital

OBJECTIVE

Translation of evidence into practice by health systems can be slow and incomplete and may disproportionately impact disadvantaged populations. Coronary heart disease is the leading cause of death among Aboriginal Australians. Timely access to effective medical care for acute coronary syndrome substantially improves survival. A quality-of-care audit conducted at a regional Western Australian hospital in 2011-2012 compared the Emergency Department management of Aboriginal and non-Aboriginal acute coronary syndrome patients. This audit is used as a case study of translating knowledge processes in order to identify the factors that support equity-oriented knowledge translation.

METHODS

In-depth interviews were conducted with a purposive sample of the audit team and further key stakeholders with interest/experience in knowledge translation in the context of Aboriginal health. Interviews were analysed for alignment of the knowledge translation process with the thematic steps outlined in Tugwell's cascade for equity-oriented knowledge translation framework.

RESULTS

In preparing the audit, groundwork helped shape management support to ensure receptivity to targeting Aboriginal cardiovascular outcomes. Reporting of audit findings and resulting advocacy were undertaken by the audit team with awareness of the institutional hierarchy, appropriate timing, personal relationships and recognising the importance of tailoring messages to specific audiences. These strategies were also acknowledged as important in the key stakeholder interviews. A follow-up audit documented a general improvement in treatment guideline adherence and a reduction in treatment inequalities for Aboriginal presentations.

CONCLUSION

As well as identifying outcomes such as practice changes, a useful evaluation increases understanding of why and how an intervention worked. Case studies such as this enrich our understanding of the complex human factors, including individual attributes, experiences and relationships and systemic factors that shape equity-oriented knowledge translation. Given the potential that improving knowledge translation has to close the gap in Aboriginal health disparities, we must choose strategies that adequately take into account the unique contingencies of context across institutions and cultures.

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.