Are we underestimating the suicide rate of middle and older-aged Indigenous Australians? An interaction between ‘unknown’ Indigenous status and age

High rates of Indigenous suicide are a distressing phenomenon that plague several postcolonial countries. In Australia, suicide is a leading cause of mortality for Aboriginal and Torres Strait Islander people. In the period 2012 to 2016, the suicide rate for Indigenous Australians was estimated to be 23.7 per 100,000, twice the rate (11.6 per 100,000) for non-Indigenous Australians. Data presented by the National Coronial Information System highlights a major disparity in suicide rates between Indigenous and non-Indigenous Australians in younger age groups; the Indigenous suicide rate was 31.5 per 100,000 among those aged 15–44 years, compared to 11.1 per 100,000 for non-Indigenous people. Meanwhile, among those aged 45 years and older, there appeared to be no or minimal disparity in suicide rates by Indigenous identification. This paper explores the interaction between age and ‘unknown’ Indigenous status in regards to deaths by suicide.