New calculations of the prevalence of rheumatic heart disease (RHD) suggest there are more than 6000 cases in Australia, four times the number estimated in a previous study.

And while 71% are Indigenous people, many in remote regions of northern Australia, 29% are non-Indigenous and often in metropolitan areas where doctors might miss the diagnosis, the authors say.

The research, published in the Journal of the American Heart Association, used data linkage techniques to access hospital and registry figures from WA, Qld, NSW, SA and the NT.

The team estimated there were 6156 people with RHD aged younger than 55 years nationwide in 2017, more than four times higher than the estimate of 1518 cases made in a Global Burden of Disease study.