Rheumatic heart disease mortality in Indigenous and non-Indigenous Australians between 2010 and 2017

Objectives To generate contemporary age-specific mortality rates for Indigenous and non-Indigenous Australians aged <65 years who died from rheumatic heart disease (RHD) between 2013 and 2017, and to ascertain the underlying causes of death (COD) of a prevalent RHD cohort aged <65 years who died during the same period.
Methods For this retrospective, cross-sectional epidemiological study, Australian RHD deaths for 2013–2017 were investigated by first, mortality rates generated using Australian Bureau of Statistics death registrations where RHD was a coded COD, and second COD analyses of death records for a prevalent RHD cohort identified from RHD register and hospitalisations. All analyses were undertaken by Indigenous status and age group (0–24, 25–44, 45–64 years).
Results Age-specific RHD mortality rates per 100 000 were 0.32, 2.63 and 7.41 among Indigenous 0–24, 25–44 and 45–64 year olds, respectively, and the age-standardised mortality ratio (Indigenous vs non-Indigenous 0–64 year olds) was 14.0. Within the prevalent cohort who died (n=726), RHD was the underlying COD in 15.0% of all deaths, increasing to 24.6% when RHD was included as associated COD. However, other cardiovascular and non-cardiovascular conditions were the underlying COD in 34% and 43% respectively.
Conclusion Premature mortality in people with RHD aged <65 years has approximately halved in Australia since 1997–2005, most notably among younger Indigenous people. Mortality rates based solely on underlying COD potentially underestimates true RHD mortality burden. Further strategies are required to reduce the high Indigenous to non-Indigenous mortality rate disparity, in addition to optimising major comorbidities that contribute to non-RHD mortality.