Endometriosis surgery in Australia is increasingly being performed in private hospitals, according to new national data, in a system where Indigenous patients rarely reach private care.

The Australian Institute of Health and Welfare report Endometriosis hospital procedures, released on Friday, found the rate of endometriosis hospitalisations rose 23 per cent over the past decade. The rate at which women and girls were admitted to hospital for any condition rose 4.7 per cent over the same period.

Endometriosis causes tissue similar to the lining of the uterus to grow outside it, and can cause chronic pain, heavy bleeding and infertility.

The AIHW estimates around one in seven women born between 1973 and 1978 had been diagnosed by the age of 44 to 49.

There were 24,689 endometriosis hospitalisations in 2024-25, up from 17,630 in 2015-16, and more than nine in 10 involved a procedure.

Of those hospitalisations involving a procedure, 71.5 per cent took place in private hospitals last financial year, up from 65.7 per cent a decade earlier.

Private hospitals accounted for 80 per cent of laparoscopic excisions, the keyhole surgery used to cut out endometriosis tissue and the most commonly performed procedure.

AIHW spokesperson Amy Young said the report was important for understanding changes in treatment and care pathways, and for informing efforts to improve health outcomes for people affected by endometriosis.

The report presents its findings by age group and hospital sector. It does not include data by Indigenous status.

The National Action Plan for Endometriosis, released by the Federal Government in 2018, set goals of improved accessibility for Aboriginal and Torres Strait Islander people and improved data capture and use.

Asked whether the new figures could be broken down, the AIHW told National Indigenous Times it held no First Nations data in the report and would not be able to provide anything quickly on procedures by First Nations status. An expansion or update of the report may be considered at a later date.

That omission matters because the private hospital system, where most endometriosis surgery now happens, is one Indigenous patients are least likely to enter.

The AIHW's Aboriginal and Torres Strait Islander Health Performance Framework found that between July 2017 and June 2019, just 12 per cent of hospitalisations involving a procedure for Indigenous Australians took place in private hospitals. For non-Indigenous Australians, the figure was 51 per cent.

In 2018-19, 21 per cent of Indigenous Australians aged 15 and over living in non-remote areas held private health insurance compared with 58 per cent of non-Indigenous Australians in the same age group and areas.

Private cover plays a bigger role in endometriosis care than in hospital care generally.

The AIHW's 2025 report, Endometriosis, found 57 per cent of endometriosis-related hospitalisations in 2022-23 were partly or fully funded by private health insurance, compared with 41 per cent of all female hospitalisations.

That report also recorded 1,300 endometriosis-related hospitalisations for Indigenous women in 2022-23, a rate of 255 per 100,000 females.

Indigenous women accounted for 2.9 per cent of endometriosis-related hospitalisations that year, against a 6.0 per cent share of all female hospitalisations.

The institute said differences between population groups could reflect variations in access to health services, including barriers to access, or differences in health-seeking behaviour, rather than differences in how common the disease is.

The same report found the endometriosis hospitalisation rate in major cities was 1.5 times the rate in remote and very remote areas, the reverse of the pattern for all female hospitalisations, where the remote rate is twice the major cities rate.

The AIHW is an independent corporate Commonwealth entity and national agency that provides statistics and information on Australia's health and welfare.