Colonoscopy outcomes in Aboriginal and Torres Strait Islander peoples
Do rates and outcomes of colonoscopy among Aboriginal and Torres Strait Islander peoples differ from those of other Australians?
Aboriginal and Torres Strait Islander people are disadvantaged across a range of health-related and socioeconomic indicators, compared with other Australians. Many factors contribute to the gap between Indigenous and non-Indigenous health, including social disadvantage (e.g. lower education and employment rates), as well as higher smoking rates, poor nutrition, physical inactivity and poor access to health services.
Overview of evidence (non-systematic literature review)
No systematic reviews were undertaken for this topic. This overview is based on selected evidence and guidelines (see Guideline development process).
Colorectal cancer rates
Aboriginal people are diagnosed with bowel cancer an average of 7.2 years younger than non-Indigenous Australians (unpublished NSW Cancer Registry data). In NSW and South Australia, 20% of bowel cancer diagnosed in Aboriginal people occurs in people under the age of 50. This compares with 6% in the non-Aboriginal population.
National data shows that Indigenous Australians have a slightly lower age-standardised bowel cancer rate than non-Indigenous Australians (52 versus 57 per 100,000) and bowel cancer mortality rate than non-Indigenous Australians (12 versus 15 per 10,000). This lower incidence and mortality may be due to lower life expectancies in Aboriginal people, fewer diagnoses due to lower participation in cancer screening, and a larger proportion of inadequate death certification and more cancers of unknown primary site amongst Aboriginal people.
Participation in the national bowel cancer screening program
The National Bowel Cancer Screening Program reports much lower participation rates amongst the Indigenous than the non-Indigenous population. Indigenous Australians, who are screened are more likely to screen positive that non-Indigenous Australians (11% versus 8% non-Indigenous), but less likely to undergo diagnostic assessment (57% versus 71%). Indigenous Australians undergoing diagnostic assessment wait longer than non-Indigenous Australians (median 64 days versus 52 days).
Uptake of services for bowel health
A 2005 North Queensland study reported that approximately 30% of Indigenous patients estimated to have colorectal cancer (CRC) attended for treatment. The authors recommended education for Indigenous people about CRC and establishing cancer units with Indigenous liaison officers. The study authors also highlighted the importance of health care providers having sufficient cultural competence to ensure Indigenous Australians’ participation in bowel cancer prevention and treatment. Training and employing more indigenous healthcare providers and working in collaboration with local Indigenous communities will also improve participation.
At a national level, achieving increased participation by Aboriginal and Torres Strait Islander people in bowel cancer surveillance also requires overcoming recognised barriers, such as incomplete enrolment in Medicare and barriers inhibiting Indigenous self-identification. Currently there are limitations to the quality of data at a national level because of incomplete capture of Indigenous status. The importance of all health care providers being cultural competent has been discussed above.
Implications for health system planning
Culturally sensitive resources are required to assist in implementation of guideline recommendations in Indigenous communities.
Carefully planned studies are also required to understand and specifically address unmet needs for surveillance colonoscopy and under-detection of CRC and possibly inflammatory bowel disease in Indigenous people.
Health system planning to improve participation in surveillance will more effectively achieve the goal of reducing bowel cancer if planning also addresses risk factors for bowel cancer of high prevalence for Indigenous people. Commonwealth and jurisdictional health plans incorporate Closing the Gap targets and the Australian Institute of Health and Welfare provides regular reports on progress towards meeting these targets. These reports are available to support health service planning and review.
- Australian Institute of Health and Welfare. Cancer in Australia 2017. Cancer series no. 101. Cat. no. CAN 100. Canberra: AIHW; 2017.
- Weir K, Supramaniam R, Gibberd A, Dillon A, Armstrong BK, O'Connell DL. Comparing colorectal cancer treatment and survival for Aboriginal and non-Aboriginal people in New South Wales. Med J Aust 2016 Mar 7;204(4):156 Available from: http://www.ncbi.nlm.nih.gov/pubmed/26937671.
- Australian Institute of Health and Welfare. National Bowel Cancer Screening Program: Monitoring report 2017. Canberra, Australia: Australian Institute of Health and Welfare;.
- Christou A, Katzenellenbogen JM, Thompson SC. Australia's national bowel cancer screening program: does it work for indigenous Australians? BMC Public Health 2010 Jun 25;10:373 Available from: http://www.ncbi.nlm.nih.gov/pubmed/20579344.
- Thompson SC, Woods JA, Katzenellenbogen JM. The quality of indigenous identification in administrative health data in Australia: insights from studies using data linkage. BMC Med Inform Decis Mak 2012 Nov 16;12:133 Available from: http://www.ncbi.nlm.nih.gov/pubmed/23157943.
- Breen N, Lewis DR, Gibson JT, Yu M, Harper S. Assessing disparities in colorectal cancer mortality by socioeconomic status using new tools: health disparities calculator and socioeconomic quintiles. Cancer Causes Control 2017 Feb;28(2):117-125 Available from: http://www.ncbi.nlm.nih.gov/pubmed/28083800.
- HealthInfoNet. Australian Indigenous HealthInfoNet. [homepage on the internet] Western Australia, Australia: Edith Cowan University; [cited 2018 Jun 29]. Available from: https://healthinfonet.ecu.edu.au/learn/health-system/closing-the-gap/.
- Australian Institute of Health and Welfare. AIHW Data Cubes..