Presented at VH 2026 (16th Australasian Viral Hepatitis Conference), held 12–14 August 2026 in Fremantle, Western Australia
Australia has made substantial progress towards blood-borne virus elimination targets, but diagnosis gaps remain. An estimated 33% of people living with hepatitis B, 12% of those living with hepatitis C and 6% of people living with HIV in Australia are undiagnosed.
Late and missed diagnoses can disproportionately affect groups who face barriers to accessing healthcare, including culturally and linguistically diverse communities and people who inject drugs. Emergency departments may provide an important opportunity to reach people who are less likely to be tested through other healthcare settings.
With opt-out testing, people are routinely tested unless they choose not to take part. We assessed the potential health and economic impact of combined hepatitis B, hepatitis C and HIV opt-out testing among people already having blood tests in emergency departments in high-prevalence urban areas in Australia.
What we did
We developed a hybrid cost-effectiveness model comparing combined blood-borne virus opt-out testing with current testing practice in emergency department settings. Using Australian data, the model used:
- a decision tree to estimate short-term outcomes, such as new diagnoses and linkage to care, and
- a lifetime Markov model to estimate longer-term health outcomes and healthcare costs from a national health service (Medicare) perspective
We also tested how changing key assumptions and inputs affected the results.
Key findings
For every 10,000 people having emergency department blood tests, combined blood-borne virus opt-out testing was estimated to:
- identify 32 additional diagnoses compared with current practice: two HIV, 14 hepatitis B and 16 hepatitis C diagnoses
- link 17 additional people to care: one with HIV, 11 with hepatitis B and five with hepatitis C
Over a lifetime, combined testing was estimated to provide additional health benefits at an additional cost of A$3,273 per quality-adjusted life year gained compared with current testing. This is well below the A$50,000 willingness-to-pay threshold applied in the model.
Combined testing remained cost-effective at lower prevalence levels, including when hepatitis C prevalence was 0.1%.
In addition to the combined approach, hepatitis C opt-out testing alone was estimated to be cost-saving, reflecting the benefits of earlier diagnosis and curative treatment.
Successfully linking people diagnosed through testing to care was an important driver of cost-effectiveness.
Implications
These findings suggest that combined blood-borne virus opt-out testing could identify more infections, link more people to care and represent good value for healthcare resources in high-prevalence urban emergency department settings in Australia. The model did not account for broader social impacts or infections prevented through reduced transmission, so it may underestimate the full benefits and cost savings.
Scaling up real-world combined blood-borne virus opt-out testing could support earlier diagnosis and help Australia progress towards its blood-borne virus elimination goals.
Read the full poster here.
To learn more about Aquarius Population Health’s work in health economic modelling, infectious diseases and population health, please visit the Aquarius website or contact us at info@aquariusph.com.
Funding and acknowledgements: This work was commissioned and funded by Gilead Sciences and carried out by Aquarius Population Health, informed by Australian expert co-authors to support clinical relevance and applicability.