Improved life expectancy for Indigenous and non-Indigenous people in the Northern Territory, 1999-2018: overall and by underlying cause of death

Objectives: To provide updated estimates of life expectancy at birth for Indigenous and non-Indigenous people in the Northern Territory,1999-2018; to quantify the contributions of changes in life years lost to disease-specific causes of death to overall changes in life expectancy. Design, setting, participants: Analysis of Australian Coordinating Registry data on underlying and nine multiple causes of death (ICD-10) for deaths in the NT, by age, sex, and Indigenous status, 1 January 1999 - 31 December 2018. Main outcome measures: Life expectancy at birth by year and 5-year period, by Indigenous status and sex; change in life expectancy by year and 5-year period, by Indigenous status and sex; contributions in changes in life years lost to leading underlying causes of death, by 5-year period, Indigenous status and sex. Results: Life expectancy for Indigenous men increased from 56.6 years in 1999 to 65.6 years in 2018 (change, 9.0 years; 95% CI, 7.9-10.0 years) and from 64.8 to 69.7 years for Indigenous women (4.9 years; 95% CI, 3.2-6.7 years); for non-Indigenous men, it increased from 77.4 to 81.0 years (3.6 years; 95% CI, 2.8-4.4 years), and from 84.3 to 85.1 years for non-Indigenous women (0.8 years; 95% CI, -0.4 to 1.9 years). Increased life expectancy for Indigenous men was primarily linked with fewer years of life lost to cancer (23% of overall change), unintentional injuries (18%), and cardiovascular disease (17%), and for Indigenous women with fewer life years lost to cancer (24%), intentional injuries (17%), and kidney disease (14%). During 1999-2018, the difference in life expectancy between Indigenous and non-Indigenous people declined by 26% for men (from 20.8 to 15.4 years) and by 21% for women (from 19.5 to 15.4 years). Conclusions: Life expectancy improved markedly during 1999-2018 for Indigenous people in the NT, particularly with respect to fewer years of life lost to cancer, injuries, and chronic disease. The smaller gains in life expectancy for non-Indigenous people were linked with improved survival for those with cancer and neurological conditions.