Jurisdictional movement among people with hepatitis B and C in Australia: implications for national data.

Objectives and importance of study Chronic hepatitis B and C are leading causes of liver cancer in Australia, and understanding prevalence, diagnosis, and care uptake is a public health priority in the context of a strategic commitment to elimination. This study aims to estimate the degree of movement between jurisdictions among people with hepatitis B and hepatitis C in Australia, to understand the impact on national notifications data and the implications for modelling of prevalence and diagnosis, and consequently uptake measures. Study type Retrospective cohort study using linked health service provision data. Methods Individuals who received Medicare services restricted to those diagnosed with hepatitis B or hepatitis C (nucleic acid testing or treatment) via Medicare during 2011-2023 were analysed. The proportion who changed jurisdictions and the proportion who had a service in multiple jurisdictions were generated, with sub-analysis by jurisdiction and among priority populations (those born overseas and Aboriginal and/or Torres Strait Islander people). Results Among the cohort (n=137,041 hepatitis B; n=252,144 hepatitis C), 9.8% of those with hepatitis B and 15.1% of those with hepatitis C resided in more than one jurisdiction, ranging from 6.7%-33.3% by jurisdiction for hepatitis B and 14.5%-42.8% for hepatitis C. This compared to 10.3% (range 8.0%-28.9%) among the total Australian population. Movement was higher among Aboriginal and Torres Strait Islander people for hepatitis B, with a different pattern by jurisdiction than the total cohort. The proportion who had a hepatitis B or hepatitis C service in multiple jurisdictions was 3.2% and 4.6%, respectively, with similar trends by state and territory. Conclusions Movement among people with hepatitis B and C was highly variable according to jurisdiction. This movement should be accounted for in the use of notifications data according to geographic area, and in assessing national progress towards viral hepatitis elimination goals.