1.05 Circulatory disease
Why is it important?
Circulatory disease is a major cause of morbidity and mortality among Australians. In recent decades, Australian mortality rates from circulatory disease have fallen, due to reduced smoking; improved management of high blood pressure and heart disease; and improved treatments for heart attack and stroke. However, increasing levels of obesity and diabetes threaten to slow or reverse these improvements. Circulatory disease is more common among Indigenous Australians and tends to occur at much younger ages (Katzenellenbogen et al. 2014; Bradshaw et al. 2010). Circulatory disease accounts for 17% of the burden of disease in Indigenous Australians (Vos et al. 2007) and 25% of mortality (see measure 1.23). Smoking levels are high among Indigenous adults, although there has been a significant reduction in recent times (see measure 2.15). Risk factors such as physical inactivity, obesity, diabetes and high blood pressure are more prevalent among Indigenous Australians than non-Indigenous Australians. Low socio-economic status is associated both with greater risk of developing circulatory disease and with lower chance of receiving appropriate treatment (Beard et al. 2008; Cunningham 2010).
In 2008–12, circulatory disease was the leading cause of death among Indigenous Australians (25% of deaths), with an age- standardised death rate 1.5 times that of non-Indigenous Australians. The leading causes of Indigenous circulatory disease deaths were ischaemic heart disease (55%), followed by cerebrovascular causes such as stroke (17%). There has been a 40% decline in circulatory disease deaths among Indigenous Australians between 1998 and 2012 and a significant narrowing of the gap between Indigenous and non-Indigenous Australians. A study in the NT between 1992 and 2004 found an increase in incidence of acute myocardial infarction and at the same time an improvement in survival both prior to and after hospital admission (You et al. 2009).
Based on self-reported data from the 2012–13 Health Survey, 13% of Indigenous Australians had a circulatory condition. This is a significant increase from 11% in 2001. Rates increased with age and 23% of those aged 25 years and over reported the condition. After adjusting for differences in the age structure of the two populations, Indigenous Australians were 1.2 times as likely to report having circulatory disease as non-Indigenous Australians. Circulatory diseases commenced at younger ages for Indigenous Australians. The greatest disparities were in the 25–54 year age groups. This disease was more common in Indigenous women (14%) than men (11%).
Indigenous Australians living in remote areas reported higher rates of circulatory disease than those in non-remote areas (18% compared with 11%). Wang et al. (2013) reported that the lifetime risk of developing heart disease among Indigenous Australians in a remote region was as high as one in two. Analysis of the 2012–13 Health Survey found that diabetes and kidney disease were common comorbidities for circulatory disease. Around 45% of Indigenous Australians aged 15 years and over reporting diabetes (and 47% of those who reporting kidney disease) also reported having circulatory diseases. Indigenous Australians were also more likely to report having circulatory disease if they lived in the most disadvantaged areas (20%) compared with most advantaged areas (10%) and if they completed schooling to Year 9 (27%) compared with those who completed Year 12 (12%). Indigenous adults who were obese had higher rates (26%) than those who were not obese (14%).
Based on a survey of GPs from April 2008 to March 2013, approximately 8% of problems managed by GPs among Aboriginal and Torres Strait Islander peoples were circulatory conditions. After adjusting for differences in the age structure of the two populations, rates for the management of hypertension and cardiac check-ups were similar to those for other Australians, yet the management rate for ischaemic heart disease was nearly twice as high. For the two years to June 2013, after adjusting for differences in the age structure of the two populations, the circulatory disease hospitalisation rate for Indigenous Australians was 1.5 times that of non-Indigenous Australians. Hospitalisation rates were higher for Indigenous males (18 per 1,000) than Indigenous females (15 per 1,000). Since 2004–05, there has been a 12% increase in hospitalisations for circulatory disease in the six jurisdictions with adequate data for trend reporting (NSW, Vic, Qld, WA, SA and the NT combined). Rates among non-Indigenous Australians remained static over this period, resulting in an increase in the difference between Indigenous and non-Indigenous rates. Ischaemic heart disease was the most common type of circulatory disease resulting in hospitalisation for Indigenous Australians (40%) followed by pulmonary and other heart diseases (31%). Diabetes and kidney disease were common comorbidities with hospitalisation rates for Indigenous Australians 7.3 times the rate for other Australians when all three diseases are present (AIHW 2014j). In 2012, Indigenous Australians aged 25 years and over had an age-standardised incidence rate of heart attacks twice that of other Australians (995 compared with 408 per 100,000) (SCRGSP 2015).
Indigenous Australians were nearly half (0.6 times) as likely to receive coronary angiography and revascularisation procedures (see measure 3.06). This disparity in therapeutic procedures has been well documented (Cunningham 2002). According to one study of the NT, Indigenous Australians were less likely to receive in-patient cardiac rehabilitation, prescription of statins on discharge, and were more likely to die in the two years after discharge (Brown 2010). Randall et al. (2013) reported that over the period 2000 to 2008, Indigenous Australians in NSW had a 37% lower rate of revascularisation in the 30 days after admission with myocardial infarction compared with non-Indigenous Australians. This disparity was largely explained by the hospital of admission (hospitals in regional and rural areas had lower revascularisation rates for all patients), a higher comorbidity burden and lower rates of private health insurance. In a separate study, the same research group found that patients admitted to smaller more remote hospitals without onsite angiography had increased risk of short-term and long-term mortality (Randall et al. 2012).
Circulatory disease problems were managed by GPs at similar rates for Indigenous Australians and other Australians. Hospitalisation rates for circulatory disease were higher among Indigenous Australians but they were less likely to receive coronary procedures when in hospital than non-Indigenous Australians. High rates of mortality due to circulatory disease indicate a failure in the areas of prevention, diagnosis and early detection, early treatment, chronic disease management, treatment and rehabilitation. A study in the NT of avoidable mortality for Indigenous Australians between 1985 and 2004 found improvements in conditions amenable to medical care but marginal improvement for conditions responsive to preventative measures. The study noted the reduction of deaths from stroke was consistent with improved drug therapies and intensive care, dedicated stroke units and surgical procedures (Li et al. 2009).
The Indigenous Australians' Health Programme, which commenced 1 July 2014, provides chronic disease prevention and management through comprehensive primary health care and outreach specialist and allied health services (see Policies and Strategies section). Under the Health and Hospitals Fund 2011 Regional Priority Round, more than $6 million is being provided in the NT to establish an Integrated Cardiac Network Service. This service will link Darwin, Alice Springs, Tennant Creek, Katherine and Gove as well as well-equipped cardiac care outreach and rehabilitation services to diagnose and manage coronary disease, rheumatic heart disease, arrhythmias, and heart failure.
The National Recommendations for the Better Cardiac Care for Aboriginal and Torres Strait Islander People Post-Forum Report, May 2014, focuses on five priority areas, including: early cardiovascular risk assessment and management; timely diagnosis of heart disease and heart failure; guideline- based therapy for acute coronary syndrome; optimisation of health status and provision of ongoing preventive care; and strengthening the diagnosis, notification and follow-up of rheumatic heart disease. These recommendations will be tested through pilots in some jurisdictions over the coming years.
The Australian Government-funded ESSENCE project 'essential service standards' articulates what elements of care are necessary to reduce disparity in access and outcomes for circulatory disease. In addition, the Australian Government funds the Lighthouse project, which aims to drive systemic change in the acute care sector to improve care and outcomes for Indigenous Australians experiencing acute coronary syndrome. Approaches that are culturally competent, family-centred, and encourage partnerships with Indigenous Australians to work collaboratively across the continuum of prevention and care, have been identified as key points for success (NHMRC 2005).
Figure 1.05-1 shows Indigenous Australians living in remote areas reported higher rates of circulatory disease than those in non remote areas (18% compared with 11%).
Source: ABS and AIHW analysis of 2012–13 AATSIHS
Figure 1.05-2 shows rates of self-reported heart and circulatory disease increased with age and 23% of those aged 25 years and over reported the condition. After adjusting for differences in the age structure of the two populations, Indigenous Australians were 1.2 times as likely to report having circulatory disease as non-Indigenous Australians. Circulatory diseases commenced at younger ages for Indigenous Australians. The greatest disparities were in the 25–54 year age groups.
Note: Total is age-standardised
Source: ABS and AIHW analysis of 2012–13 AATSIHS
Figure 1.05-3 shows there has been a 40% decline in circulatory disease deaths among Indigenous Australians between 1998 and 2012 and a significant narrowing of the gap between Indigenous and non-Indigenous Australians.
Source: ABS and AIHW analysis of National Mortality Database
Figure 1.05-4 shows Indigenous Australians have higher rates of hospitalisation for circulatory disease across all age-groups except for 65 years and over.
Source: AIHW analysis of National Hospital Morbidity Database