The estimated prevalence of dementia in the Northern Territory's Indigenous population is three times that for non-Indigenous residents, according to research published in the Medical Journal of Australia.

Researchers led by Dr Shu Qin Li, senior epidemiologist with the NT Department of Health, analysed data for 784 dementia cases diagnosed in the NT between January 2008 and December 2011.

The estimated prevalence of dementia for the total NT population aged 45 years and over, was 1.6 cases per 100 population, with a prevalence of 1.1 per 100 in the non-Indigenous population. In the Indigenous population, however, the estimated prevalence was 3.7 per 100. Additionally, the researchers found that dementia occurred earlier - at a median age of 72 years - in the Indigenous population than in the non-Indigenous (79 years).

"The prevalence of dementia among NT Indigenous people aged 45 years and over was much higher than national estimates", the researchers wrote.

Of total diagnosed cases, 54.0% were women, and 39.7% were Indigenous.

"NT has the fastest growing older population of all Australian states, and the prevalence of dementia in NT will continue to increase", Dr Li wrote. "The finding of early onset and high incidence of dementia suggests that the burden of dementia among the NT Indigenous population will continue to increase, along with both the increase in number of older Indigenous people and improved life expectancy.

"This study demonstrates the opportunity to use existing administrative data to inform a significant knowledge gap in population-level data. In this case, the results highlight the specific and emerging needs in the NT Indigenous population.

"More generally in Australia, large-scale population studies are warranted in order to better understand the burden, regional variation and social costs of dementing conditions."