Lyn Dimer

Incidence of and Case Fatality Following Acute Myocardial Infarction in Aboriginal and Non-Aboriginal Western Australians (2000–2004): A Linked Data Study

BACKGROUND Despite Coronary Heart Disease exacting a heavy toll among Aboriginal Australians, accurate estimates of its epidemiology are limited. This study compared the incidence of acute myocardial infarction (AMI) and 28-day case fatality (CF) among Aboriginal and non-Aboriginal Western Australians aged 25-74 years from 2000-2004. METHODS Incident (AMI hospital admission-free for 15 years) AMI events and 28-day CF were estimated using person-based linked hospital and mortality data. Age-standardised incidence rates and case fatality percentages were calculated by Aboriginality and sex. RESULTS Of 740 Aboriginal and 6933 non-Aboriginal incident events, 208 and 2352 died within 28 days, respectively. The Aboriginal age-specific incidence rates were 27 (males) and 35 (females) times higher than non-Aboriginal rates in the 25-29 year age group, decreasing to 2-3 at 70-74 years. The male:female age-standardised incidence rate ratio was 2.2 in Aboriginal people 25-54 years compared with 4.5 in non-Aboriginal people. Aboriginal age-standardised CF percentages were 1.4 (males) and 1.1 (females) times higher at age 25-54 years and 1.5 times higher at age 55-74 years. CONCLUSION These data suggest higher CF and, more importantly, AMI incidence contribute to the excess ischaemic heart disease mortality in Aboriginal Western Australians. The poorer cardiovascular health in Aboriginal women, particularly in younger age groups, should be investigated.

Exploring the impact of an aboriginal health worker on hospitalised aboriginal experiences: Lessons from cardiology

To enhance Aboriginal inpatient care and improve outpatient cardiac rehabilitation utilisation, a tertiary hospital in Western Australia recruited an Aboriginal Health Worker (AHW). Interviews were undertaken with the cardiology AHW, other hospital staff including another AHW, and recent Aboriginal cardiac patients to assess the impact of this position. The impact of the AHW included facilitating culturally appropriate care, bridging communication divides, reducing discharges against medical advice, providing cultural education, increasing inpatient contact time, improving follow-up practices and enhancing patient referral linkages. Challenges included poor job role definition, clinical restrictions and limitations in AHW training for hospital settings. This study demonstrates that AHWs can have significant impacts on Aboriginal cardiac inpatient experiences and outpatient care. Although this study was undertaken in cardiology, the lessons are transferable across the hospital setting.

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

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.

Complex impact of remoteness on the incidence of myocardial infarction in Aboriginal and non-Aboriginal people in Western Australia

OBJECTIVE To determine the impact of remoteness on Aboriginal and non-Aboriginal myocardial infarction incidence rates in men and women of different ages. DESIGN Descriptive study. SETTING Western Australia. PARTICIPANTS Incident cases of myocardial infarction in Western Australia from 2000-2004 identified from person-linked files of hospital and mortality records. Analysis was undertaken for Aboriginal and non-Aboriginal populations, separately and combined, by broad age group, sex and remoteness. MAIN OUTCOME MEASURE Incidence of myocardial infarction. RESULTS In the combined analysis, age-standardised incidence was significantly higher for men in very remote areas (rate ratio 1.31: 95% confidence interval (CI), 1.19-1.45) and in women in both regional (rate ratio 1.12: 95% CI, 1.01-1.20) and very remote (rate ratio 2.05: 95% CI, 1.75-2.41) areas. Aboriginal rates were substantially higher than non-Aboriginal rates in all substrata. Compared with metropolitan people, regional Aboriginal men and very remote non-Aboriginal men aged 25-54 years had significantly higher incidence rates. For the remaining rural strata, there was either no geographical disadvantage or inconclusive findings. CONCLUSIONS Non-metropolitan disadvantage in myocardial infarction rates is confirmed in regional areas and women in very remote areas. This disadvantage is partly explained by the high rates in Aboriginal people. Non-metropolitan dwellers are not uniformly disadvantaged, reflecting the interplay of the many factors contributing to the complex relationship between myocardial infarction incidence and sex, age, Aboriginality and residence. Aboriginal Western Australians in all regions and young non-Aboriginal men living in very remote areas need to be targeted to reduce disparities in myocardial infarction.

Beyond the rhetoric: how can non-government organisations contribute to reducing health disparities for Aboriginal and Torres Strait Islander people?

The prevailing disparities in Aboriginal health in Australia are a sobering reminder of failed health reforms, compounded by inadequate attention to the social determinants shaping health and well-being. Discourse around health reform often focuses on the role of government, health professionals and health institutions. However, not-for-profit health organisations are also playing an increasing role in health policy, research and program delivery across the prevention to treatment spectrum. This paper describes the journey of the National Heart Foundation of Australia in West Australia (Heart Foundation WA hereafter) with Aboriginal employees and the Aboriginal community in taking a more proactive role in reducing Aboriginal health disparities, focusing in particular on lessons learnt that are applicable to other non-government organisations. Although the Heart Foundation WA has employed and worked with Aboriginal people and has long identified the Aboriginal community as a priority population, recent years have seen greater embedding of this within its organisational culture, governance, policies and programs. In turn, this has shaped the organisations response to external health reforms and issues. Responses have included the development of an action plan to eliminate disparities of cardiovascular care in the hospital system, and collaboration and engagement with health professional groups involved in delivery of care to Aboriginal people. Examples of governance measures are also described in this paper. Although strategies and the lessons learnt have been in the context of cardiovascular health disparities, they are applicable to other organisations across the health sector. Moreover, the most powerful lesson learnt is universal in its relevance; individual programs, policies and reforms are more likely to succeed when they are underpinned by whole of organisation ownership and internalisation of the need to redress disparities in health.

Variable effects of prevalence-correction of population denominators on differentials in myocardial infarction incidence: a record linkage study in Aboriginal and non-Aboriginal Western Australians

OBJECTIVES To investigate the impact of prevalence correction of population denominators on myocardial infarction (MI) incidence rates, rate ratios, and rate differences in Aboriginal vs. non-Aboriginal Western Australians aged 25-74 years during the study period 2000-2004. STUDY DESIGN AND SETTING Person-based linked hospital and mortality data sets were used to estimate the number of prevalent and first-ever MI cases each year from 2000 to 2004 using a 15-year look-back period. Age-specific and -standardized MI incidence rates were calculated using both prevalence-corrected and -uncorrected population denominators, by sex and Aboriginality. RESULTS The impact of prevalence correction on rates increased with age, was higher for men than women, and substantially greater for Aboriginal than non-Aboriginal people. Despite the systematic underestimation of incidence, prevalence correction had little impact on the Aboriginal to non-Aboriginal age-standardized rate ratios (6% and 4% underestimate in men and women, respectively), although the impact on rate differences was more marked (12% and 6%, respectively). The percentage underestimate of differentials was greater at older ages. CONCLUSION Prevalence correction of denominators, while more accurate, is difficult to apply and may add modestly to the quantification of relative disparities in MI incidence between populations. Absolute incidence disparities using uncorrected denominators may have an error >10%.

“In Their Own Voice”—Incorporating Underlying Social Determinants into Aboriginal Health Promotion Programs

Despite growing acknowledgement of the socially determined nature of health disparities among Aboriginal people, how to respond to this within health promotion programs can be challenging. The legacy of Australia’s assimilation policies have left profound consequences, including social marginalisation, limited educational opportunities, normalisation of premature death, and entrenched trauma. These social determinants, in conjunction with a reluctance to trust authorities, create barriers to accessing healthcare services for the prevention, treatment, and rehabilitation of chronic disease. The Heart Health program is a culturally sensitive cardiac rehabilitation program run at the local Aboriginal Medical Service in Perth, Western Australia that has since moved beyond cardiac education to provide a holistic approach to chronic disease management. A participatory action research framework was used to explore Heart Health participant and service provider perspectives on the barriers, enablers, and critical success factors to program participation and behaviour change. Thematic analysis of interview transcripts was undertaken, and through yarning (Aboriginal storytelling) sessions, many participants made unprompted reference to the impacts of white settlement, discrimination, and the forced fracturing of Aboriginal families, which have been explored in this paper reiterating the need for a social determinants lens to be taken when planning and implementing Aboriginal health promotion programs.