Why are Indigenous Australians less likely than other Australians to receive a kidney transplant?
In 2011–12, one in ten Australian adults (around 1.7 million people) had biomedical signs of Chronic Kidney Disease (CKD). CKD accounts for 16 per cent of all hospitalisations and one in nine deaths. Indigenous Australians are five times as likely to be hospitalised for CKD and four times as likely to die from CKD as non-Indigenous Australians.
Although Indigenous Australians are disproportionately affected by kidney disease, they are less likely to be added to the transplant waiting list and less likely to move from the waiting list to transplantation than non-Indigenous Australians.
In this issue of In Brief we explore some of the reasons Indigenous Australians are less likely to receive a kidney transplant.
Our kidneys act as the body’s waste filtration system, removing excess water and unwanted chemicals or waste from the blood. Kidney disease – also called ‘renal disease’ – is a general term used to describe a condition in which the kidneys are damaged and do not function as they should.
CKD is defined as kidney damage and/or reduced kidney function that lasts for 3 months or longer. In 2011–12, one in ten Australian adults (around 1.7 million people) had biomedical signs of CKD. CKD accounts for 16 per cent of all hospitalisations and one in nine deaths.
CKD is categorised into five stages according to the severity of kidney damage and reduced kidney function. End-stage kidney disease (ESKD) is the most severe manifestation of CKD. Kidney disease is sometimes called a ‘silent disease’, as there are often few or no symptoms in early stages of CKD. Up to 90 per cent of kidney function can be lost before symptoms appear. As a result, many people are unaware that they have the condition.
CKD is largely preventable as many of its risk factors are modifiable. The most common causes of CKD are high blood pressure and diabetes. Other risk factors for developing CKD include:
• established heart problems
• being 60 years of age
• family history of kidney failure
• history of acute kidney injury
• having Aboriginal or Torres Strait Islander origin.
In the early and middle stages of CKD, treatment is focused on slowing the progress of the disease, preventing cardiovascular disease, and preventing and managing complications of CKD. Patients with ESKD require kidney replacement therapy – a kidney transplant or dialysis – to survive.
Kidney transplantation is considered the optimal treatment for most patients with ESKD because quality of life and life expectancy are often better than in people who are treated with dialysis. However, a shortage of donor kidneys means that not everybody who might benefit from a kidney transplant can get one. Because of this, preference is given to patients who have a good prospect of successful transplantation and reasonable life-expectancy following transplantation.
Kidneys are the most common organs in demand, with 995 Australians on the kidney transplant waiting list in January 2017. In some instances kidney transplant recipients receive a kidney donation from a living donor – usually a friend or family member. However, most transplanted organs come from deceased donors. The average waiting time for a deceased donor is 3 years.
Kidney disease among Indigenous Australians
CKD is a significant health problem for all Australians, but particularly so for Indigenous Australians. Aboriginal and Torres Strait Islander peoples, especially those who live in remote communities, are at high risk of developing CKD.
Although Indigenous Australians are disproportionately affected by ESKD, they are less likely to be added to the transplant waiting list and less likely to move from the waiting list to transplantation.
Recently, AMA President Dr Michael Gannon called for urgent attention to be given to addressing the unacceptable rate of kidney transplantation for Indigenous Australians.
In the following sections we explore some of the reasons Indigenous Australians have poor access to kidney transplantation.
The greater burden of comorbid illness among Indigenous Australians is one factor that may lead to fewer patients being deemed medically unsuitable for transplantation. Comorbid medical conditions that may affect patients’ chances of a successful outcome include cardiac disease, chronic lung disease, cirrhosis of the liver, peripheral vascular disease and cerebrovascular disease.
However, higher rates of comorbidity may only partly explain differences in access to transplantation. A national cohort study found that lower rates of acceptance onto the transplant waiting list and a lower rate of moving from the waiting list to transplantation were not explained by differences in age, sex, comorbidities or cause of disease.
Indigenous Australians have poorer outcomes following kidney transplantation, particularly in terms of infectious complications. Graft survival – either loss of graft function or death of the patient – is poorer among Aboriginal Australians, whether the graft is from a living or deceased donor.
Referral is generally defined as the time period between the first nephrology evaluation and initiation of dialysis. People who are referred earlier have been found to live longer, spend less time in hospital and are better prepared for dialysis than people who were referred late.
Late referral of Indigenous patients has been a key issue of concern for some time. However, most recent data indicate that the percentage of Aboriginal and Torres Strait Islander people referred late for treatment has steadily improved from 2011–15, with similar rates and patterns seen in the non-Indigenous population over the same period.
Human leucocyte antigens (HLA)
Antibodies to human leucocyte antigens (HLA) are an important barrier to transplantation. The presence of antibodies to HLAs is associated with graft dysfunction, transplant rejection and poorer survival. HLA matching is a practice that aims to match deceased donor kidneys to recipients on the waiting list with a similar immunologic ‘fingerprint’.
The number of HLA mismatches is significantly greater among Indigenous ESKD patients compared to non-Indigenous ESKD patients. The challenge in finding a matching donor is potentially compounded by substantially lower rates of living and deceased donors from among Indigenous Australians.
Indigenous Australians are sometimes regarded by specialists as ‘non-compliers’, which may negatively affect their referral for a transplant. An Australian study exploring the views of 19 nephrologists found that Indigenous patients were commonly categorised as both non-compliant and high-risk candidates for transplantation. However, the definition and assessment of ‘compliance’ were neither formal nor systematic. There was also uncertainty about the value of compliance status in predicting post-transplantation outcomes.
Systemic racism is another factor that likely contributes to the low rate of kidney transplantation among Indigenous Australians. Systemic racism involves requirements, conditions, practices, policies or processes that maintain and reproduce avoidable and unfair inequalities across ethnic/racial groups. For a discussion about race and health, see Dr Campbell Aitken’s In Brief post in May 2018.
As a group, Indigenous Australians experience higher levels of socio-economic disadvantage, lower educational attainment and poorer health literacy than their non-Indigenous counterparts. These factors can detrimentally affect their engagement with the health system and their adherence to treatment plans. Indigenous Australians in remote communities also face additional challenges in terms of access to services, education and tertiary level treatments such as dialysis.
A study conducted in 2005–6 found that Indigenous Australians felt uninformed, alienated from the health care system and experienced difficulty engaging in treatment.
More recently, Devitt and colleagues found that Indigenous ESKD patients displayed a very high level of positive interest in transplantation but felt poorly informed about transplantation, with most having a rudimentary understanding of the notion of transplantation and little understanding of eligibility criteria, the transplant procedure and associated risks. These patients experienced multiple communication barriers.
Dr Paul Lawton, a kidney specialist and researcher at the Menzies School of Health Research, recently noted that:
“We’ve organised our systems to deal very well right around Australia for providing really good services for non-indigenous Australians but we don’t organise our systems of care to deal with indigenous Australians”.
Indigenous Australians suffer a disproportionate burden of CKD but are less likely to receive a kidney transplant when compared with their non-Indigenous counterparts. The reasons for this disparity are complex and multi-faceted.
A better understanding of the barriers faced by Indigenous Australians when accessing kidney transplantation is sorely needed in order to improve support services and facilitate strategies to improve equity in transplantation.