New RHD diagnoses

In this report, a ‘new’ rheumatic heart disease (RHD) diagnosis is defined as one that was diagnosed between 1 January 2015 and 31 December 2019. In most cases, it is not possible to identify a year of onset for RHD as the condition may be asymptomatic initially. The analysis is based on year of diagnosis.

In 2015–2019, there were 1,776 reports of new RHD diagnoses in Queensland, South Australia, Western Australia and the Northern Territory (4 per 100,000 population). Of these, 953 notifications (56%) were made in people with no previous notification of ARF.

For the four jurisdictions combined, RHD diagnosis rates between 2015 and 2019 have remained relatively stable, at around 3 to 4 diagnoses per 100,000 population annually. During this period, diagnosis rates varied by state and territory:

  • South Australia had less than 1 diagnosis per 100,000 population
  • Western Australia had 2 diagnoses per 100,000
  • Queensland had 4 diagnoses per 100,000
  • Northern Territory had 47 diagnoses per 100,000 (Figure 9).
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Indigenous Australians and newly diagnosed RHD

Of the 1,776 new RHD diagnoses among all Australians in 2015–2019, 75% (1,325) were Indigenous Australians (60 per 100,000 population). The annual combined rate in Queensland, Western Australia, South Australia and the Northern Territory increased from 50 to 73 per 100,000 (213 diagnoses to 332 diagnoses) between 2015 and 2018—but decreased in 2019 to 63 per 100,000 (284 diagnoses) (Figure 9). During the same period, the overall diagnosis rate for Indigenous Australians was around 63 times the rate for non-Indigenous Australians (60 per 100,000, compared with less than 1 per 100,000, respectively).

In 2015–2019, most new RHD diagnoses among Indigenous Australians were from the Northern Territory. The rate of new diagnoses in the Northern Territory was 3 times that of Western Australia, 3 times that of Queensland and 6 times that of South Australia.

The remainder of the information on RHD in this report (with the exception of deaths) relates to Indigenous Australians, due to the relatively small number of new cases recorded among non-Indigenous Australians.

Age and sex and RHD

In 2015–2019, for all new RHD cases diagnosed among Indigenous Australians:

  • the rate of new RHD diagnosis for females was nearly 2 times that for males (76 and 44 diagnoses per 100,000 population, respectively)
  • females had higher rates compared to males in all age groups, excluding those aged 5–14
  • 55% were aged under 25 years at diagnosis (723 people)
  • 9 children were aged under 5 and 418 children were aged between 5 and 14 at the time of RHD diagnosis (Figure 9)

The median age at diagnosis for Indigenous Australians was 22 years (17 years for males and 24 years for females), compared with 50 years for non-Indigenous Australians. 

New RHD priority at diagnosis

An individual’s priority status (Box 5) determines the recommended care plan and schedule given their clinical and personal needs. This status may change over time as their condition and needs change. 

Box 5: RHD Priority status and health state definitions

Classification

Definition

Priority 1: Severe RHD

Severe valvular disease or

Moderate/severe valvular lesion with symptoms or

Mechanical prosthetic valves, tissue prosthetic valves and valve repairs (including balloon valvuloplasty)

Priority 2: Moderate RHD Any moderate valve lesion in the absence of symptoms and with normal left ventricular function

Priority 3: Mild RHD

ARF with no evidence of RHD or

Trivial to mild valvular disease

Priority 4: Inactive

Patients with a history of ARF (no RHD) for whom secondary prophylaxis has been ceased

Source: Adapted From the Australian Guideline for Prevention, Diagnosis and Management of Acute Rheumatic Fever and Rheumatic Heart Disease, 2012.

In 2015–2019, of the 1,319 Indigenous Australians with new RHD diagnoses:

  • 55% had mild RHD when first diagnosed (725 diagnoses)
  • 26% had moderate RHD (347)
  • 17% had severe RHD (228) (Box 5).

This distribution was similar across states and territories, with the exception of South Australia with 9% of cases being severe at diagnosis. Distribution varied by age group, with relatively large proportions of severe cases in the 45 and over age group (25% of cases). There were too few cases among those aged 0–4 to draw conclusions regarding severity at diagnosis (Figure 10).

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