Why is it important?
Diabetes is a long-term (chronic) condition in which blood glucose levels become too high because the body produces little or no insulin, or cannot use insulin properly. Over many years, high blood glucose levels can damage various parts of the body, especially the heart and blood vessels, eyes, kidneys and nerves, resulting in permanent disability, mental health problems, reduced quality of life and premature death (AIHW 2008a). High blood glucose levels can cause complications for both the mother and baby during pregnancy. Diabetes is responsible for 12% of the health gap between Indigenous and non-Indigenous Australians (Vos et al. 2007). Diabetes rates are higher among Indigenous Australians than non-Indigenous Australians in every socioeconomic status group (Cunningham 2010).
There are several forms of diabetes. The most common form is Type 2, which accounted for 85% of all diabetes in Australia in 2011–12 (ABS 2012a). Type 2 diabetes is a significant contributor to morbidity and mortality for Aboriginal and Torres Strait Islander peoples. It is more common in people who are physically inactive, have a poor diet, and are overweight or obese (AIHW 2008a). Other factors such as heredity, low birthweight, intra-uterine factors and excessive alcohol consumption are also associated with increased risk. Type 1 diabetes, the most common form of diabetes in children, is generally thought to be rare among Aboriginal and Torres Strait Islander peoples although misclassification problems with Type 2 diabetes make this difficult to ascertain (AIHW 2002).
The 2012–13 Health Survey included blood tests for measuring diabetes prevalence. In 2012–13, 11% of Indigenous Australians aged 18 years and over had diabetes. After adjusting for age differences in the two populations, this was more than 3 times as high as for non-Indigenous Australians. This comprised 9.6% of Indigenous adults with known diabetes and 1.5% with diabetes newly diagnosed by the blood test results, suggesting that approximately 14% of cases of diabetes were previously undiagnosed. Indigenous adults were twice as likely to have undiagnosed diabetes as non-Indigenous adults. In addition, 5% of Indigenous Australians had blood test results showing impaired fasting plasma glucose, which means they were at high risk of developing diabetes, which was 1.8 times the non-Indigenous rate. Of those Indigenous adults with known diabetes, 61% had blood test results suggesting the condition was not being managed effectively. This was 1.4 times as high as non-Indigenous Australians (44%). Half (53%) of Indigenous Australians with diabetes also had signs of chronic kidney disease (see measure 1.10).
Measured rates of diabetes for Indigenous adults were more than double in remote areas (21%) compared with non-remote areas (9%). Newly diagnosed diabetes was 5 times as high in remote as non-remote areas (4.8% compared with 0.9%). Rates of diabetes were highest in the NT (19%) and lowest in Qld (8%). Indigenous men and women had similar rates of diabetes (10% compared with 12%). Among Indigenous Australians, diabetes problems started in younger age groups than for non-Indigenous Australians. Higher rates of diabetes were evident from 35 years onwards and by 55 years and over, one-third of Indigenous Australians had diabetes. There was a statistically significant relationship between the prevalence of diabetes and selected social determinants of health and risk factors such as socio-economic status, educational attainment, weight, and blood pressure.
In 2005–07, Aboriginal and Torres Strait Islander mothers were more likely to experience pre-existing diabetes affecting pregnancy (3 to 4 times the non-Indigenous rate) and to develop gestational diabetes mellitus (GDM) (twice the non-Indigenous rate). Indigenous mothers with preexisting diabetes were more likely to deliver pre-term (32%), compared with Indigenous mothers with GDM (14%) and Indigenous mothers without diabetes (13%) (AIHW 2010b).
Of Indigenous Australians in non-remote areas self-reporting diabetes, 69% had a blood test to check for diabetes control in the last 12 months and 68% had their feet checked in the last 12 months. In addition, 30% of Indigenous Australians with diabetes in non-remote and remote areas combined were using insulin, 64% were taking medicine/tables and 80% had taken lifestyle action relating to diet, weight loss and exercise.
The prevalence of diabetes among Indigenous Australians in selected remote communities was 5 to 10 times as high as in the general community (Hoy et al. 2007; Kondalsamy-Chennakesavan et al. 2008; Zhao et al. 2008). A NSW study of young people aged 10–18 years found the incidence rate of diabetes for Indigenous children was 6 times the rate for non-Indigenous children (Craig et al. 2007). An analysis of the Fremantle Diabetes Study found diabetes prevalence for Aboriginal people to be more than double the rate for non-Indigenous Australians, with average age at diagnosis 14 years younger (Davis et al. 2007). An 11 year prospective cohort study of 686 Indigenous Australians in a remote NT Indigenous community found that half of Indigenous men and 70% of Indigenous women were at risk of developing diabetes by age 60 (Wang et al. 2010a).
A survey of GPs from April 2008 to March 2013 showed that 5% of all problems managed by GPs among Indigenous Australians were for diabetes. Type 2 diabetes accounted for 94% of all diabetes problems managed among Indigenous Australians. After adjusting for differences in the age structure of the two populations, GPs managed diabetes problems among Indigenous patients at 2.8 times the rate for other Australian patients.
In the two years to June 2013, rates of hospitalisations with a principal diagnosis of diabetes were 4.2 times as high for Indigenous Australians as for non-Indigenous Australians. Around 61% of hospitalisations for diabetes among Indigenous Australians were for Type 2 diabetes, 17% for Type 1 diabetes and a further 21% for diabetes during pregnancy. Hospitalisation rates were higher among those living in remote areas (11 per 1,000 in remote areas and 10 per 1,000 in very remote areas) than those in major cities (4 per 1,000). Complications of diabetes such as lower limb amputations have been found to be more common among Indigenous Australians than non-Indigenous Australians (Health WA 2008).
During the period 2008–12, 8% of Indigenous deaths were due to diabetes, and death rates from diabetes were 6 times the non-Indigenous rate. Diabetes was the second leading cause of the gap in death rates behind circulatory disease. There has been no improvement in death rates from diabetes for Indigenous Australians over the last 15 years. Often, it is not diabetes itself that directly leads to death and as a result the complication is listed as the cause of death (AIHW 2014k). In 2008–12, in NSW, Qld, WA, SA and the NT there were 2,344 deaths among Indigenous Australians where diabetes was listed as an associated cause of death.
Diabetes is more common among Aboriginal and Torres Strait Islander peoples than other Australians, as measured by blood tests as part of the Health Survey and GP consultations. Hospitalisations and death rates for diabetes are both high, pointing to possible issues in secondary prevention. Challenges for decision makers include maintaining a policy emphasis on primary prevention (nutrition, physical activity, smoking, alcohol, early detection) while implementing strategies to achieve effective secondary prevention (such as primary care including allied health, and blood sugar control) and appropriate acute care to treat serious complications as they arise. Aboriginal and Torres Strait Islander peoples do not constitute a homogeneous group with respect to socioeconomic status or diabetes prevalence (Cunningham 2010). Family centred approaches that support the knowledge base for effective self- management are recommended (NHMRC 2005; Griew et al. 2007).
The Diabetes Care Project pilot commenced on 1 July 2011, testing new models of health care arrangements for people with Type 1 and Type 2 diabetes. The pilot is currently in the evaluation stage. The results from the pilot will be used to inform future policy development for the management of chronic disease. The Indigenous Australians' Health Programme, which commenced 1 July 2014, provides diabetes prevention and management through comprehensive primary health care and initiatives such as nationwide tobacco reduction and healthy lifestyle promotion activities, a care coordination and outreach workforce based in Medicare Locals and Aboriginal Community Controlled Health Organisations and GP, specialist and allied health outreach services serving urban, rural and remote communities. Additionally, the Australian Government provides GP health assessments for Indigenous Australians under the MBS, of which blood pressure measurement is one key element, along with follow-on care and incentive payments for improved management, and cheaper medicines through the PBS.
Figure 1.09-1 shows the proportion of Aboriginal and Torres Strait Islander peoples reporting diabetes/high sugar levels in 2012–13, by remoteness. Measured rates of diabetes for Indigenous adults were more than double in remote areas (21%) compared with non remote areas (9%).
Source: ABS analysis of 2012–13 AATSIHS
Figure 1.09-2 shows the proportion of Aboriginal and Torres Strait Islander peoples by selected jurisdiction. The highest proportion was in the NT (19%) and the lowest was in Qld (8%).
Source: ABS analysis of 2012–13 AATSIHS
Figure 1.09-3 shows among Indigenous Australians, diabetes problems started in younger age groups than for non-Indigenous Australians. Higher rates of diabetes were evident from 35 years onwards and by 55 years and over one-third of Indigenous Australians had diabetes.
Source: ABS analysis of 2012–13 AATSIHS
Figure 1.09-4 shows age-specific hospitalisation rates for a principal diagnosis of diabetes (rate per 1,000 population). Data is presented for Aboriginal and Torres Strait Islander peoples and non-Indigenous Australians from July 2011 to June 2012. Data is presented for the following age groups: 0-4 years; 5-14 years; 15-24 years; 25-34 years; 35-44 years; 45-54 years; 55-64 years; and 65 years and over. Refer to the findings section of this measure for a description of key results found in this figure.
Source: AIHW analysis of National Hospital morbidity database