Secondary prophylaxis in Indigenous Australians

This section focuses on BPG adherence amongst Indigenous Australians who were prescribed BPG on a 28-day regimen before 31 January 2017, who did not cease BPG before 31 December 2017, and who received at least one dose in 2017.  If a person had more than one diagnosis (for example, of ARF and of RHD), they were included in the analysis only once. Those on a different regimen or an alternative treatment (i.e. not BPG) were excluded.

In total 3,372 people received any prophylaxis in 2017. Qld had 1,041 people on preventive penicillin in 2017 and there were 582 in WA, 118 in SA and 1,631 NT. Of these, 2,630 people were eligible for inclusion in further adherence calculations. They were located in NT (1,240), QLD (871), WA (438) and SA (81).  Because they were on a 28 day schedule for the entire year, this group were able to receive at least 13 doses of BPG. Of these:  

  • 15% (394 people) received 100% or more of their prescribed doses
  • 21% (548 people) received 80% to 99% of their prescribed doses
  • 37% (964 people) received 50% to 79% of their prescribed doses
  • 28% (724 people) received less than 50% of their prescribed doses.

For all states and territories, the most common level of adherence was receiving 50–79% of prescribed doses.

Adherence of 100% is the gold standard for all people on prophylactic treatment. Some people may receive more than 13 doses due to their particular schedule. The proportion of Indigenous Australians receiving 13 or more doses of BPG in one year was 23% in NT (280 people), 33 % SA (27 people), 7.1% in Qld (62 people) and 6% in WA (25 people). 

At a population level, the proportion of people receiving at least 80% of their scheduled doses is used as an indicator of adherence which is likely to protect against ARF recurrences. In 2017, 36% of Indigenous Australians (942 people) received at least 80% of doses. The proportion of people achieving at least 80% adherence was greatest in SA (63%, 51 people), the NT (46%, 573 people), followed by 27% in WA (118 people) and 23% in Qld (200 people).

Figure 1: Proportion of Indigenous Australians on BPG by adherence level and state and territory, 2017

Figure 1: This stacked vertical bar chart shows the proportion of adherence for all Indigenous ARF and/or RHD cases on prophylactic treatment in 2017, by state and territory. SA has the highest proportion of cases with 100+%25 adherence, followed by NT. More information is located in the data tables, BPG Table 3.

Note: People on BPG can have more than 13 doses in one year, therefore 100% of doses is defined as 100%+ of doses.

Source: AIHW analysis of National Rheumatic Heart Disease data collection

Adolescents and young adults (aged 15–24) had generally lower adherence than other age groups, with almost one-third of people of this age receiving less than half of their prescribed doses. 40% of 5–14 and 25–44 year olds received at least 80% of their prescribed doses.

Table 1: Proportion of Indigenous Australians on BPG by adherence level and age, 2017

1-49% adherence

16.3

32.5

31.7

14.0

27.5

724

50–79% adherence

37.3

38.5

34.8

34.0

36.7

964

80–99% adherence

33.3

27.9

17.9

19.5

20.0

20.8

548

100% + adherence

66.7

18.5

11.1

14.0

32.0

15.0

394

Total %

100.0

100.0

100.0

100.0

100.0

100.0

100.0

Total number

n.p.

584

977

916

150

2630

2630

Adherence level

0–4 years

5–14 years

15–24 years

25–44 years 

45 years and over

Total%

Total number

Note: People on BPG can have more than 13 doses in one year, therefore 100% of doses is defined as 100%+ of doses.

Source: AIHW analysis of National Rheumatic Heart Disease data collection

The adherence pattern was similar for males and females. Thirty-seven per cent of males (381 people) and 35% of females (1033 people) achieved at least 80% adherence. Around one quarter of males (29%) and females (26%) received 50% or less of their prescribed doses.

Figure 2: Proportion of Indigenous Australians on BPG by adherence level and sex, 2017

Figure 2: This vertical bar chart shows the proportion of adherence for all Indigenous ARF and/or RHD cases on prophylactic treatment in 2017, by sex. The most common level of adherence for both males and females was 50–79%25. More females than males achieved adherence of 100+%25. More information can be found in the data tables, BPG Table 1.

Note: People on BPG can have more than 13 doses in one year, therefore 100% of doses is defined as 100%+ of doses.

Source: AIHW analysis of National Rheumatic Heart Disease data collection