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National Strategies Workshop Hepatitis B: Modelling. Benjamin Cowie. Shifting focus – Hepatitis B. Major health issue worldwide 350-400 million with chronic HBV, over a million deaths/yr Hepatitis B is the 10 th leading cause of death worldwide
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National Strategies WorkshopHepatitis B: Modelling Benjamin Cowie
Shifting focus – Hepatitis B • Major health issue worldwide • 350-400 million with chronic HBV, over a million deaths/yr • Hepatitis B is the 10th leading cause of death worldwide • Hepatitis B is the 2nd most important human carcinogen • Chronic hepatitis B: 15-25% will die from the complications of cirrhosis or from hepatocellular carcinoma (HCC). • Most reliable Australian estimate: 170,000 people with chronic hepatitis B, over 1 million ever infected • HCC (most attributable to chronic viral hepatitis) is the joint fastest increasing cause of cancer death in Australia Lavanchy 2004, Previsani 2002, Gidding 2007, Kirby ASR 2011, AIHW 2010
Cancer in New South WalesIncidence and Mortality Report 2008
National Hepatitis B Strategy 2010-2013 • Three key objectives, with associated indicators – some of which lend themselves to modelling approaches: • Reduce hepatitis B infections • Incidence of hepatitis B • Reduce the proportion of people with chronic hepatitis B who have not been diagnosed • Estimated proportion of people with chronic hepatitis B who have not been diagnosed • To improve the health and wellbeing of people with chronic hepatitis B • Proportion of people with chronic hepatitis B dispensed drugs for hepatitis B infection through the Highly Specialised Drugs Program
Australian HBV Model, VIDRL • Deterministic compartmental model • Dynamic force of infection (FoI) • Constructed using Berkeley Madonna v8.3.14 • Entire Australian population • Incorporating • age structure • migration • vaccination • NOT antiviral therapy
Incidence - and prevalence - of HBVImpact of vaccination • Under current vaccination uptake, the number of incident infections in Australia is predicted to have peaked in 2000 and plateau at ≈ 2000 per year – representing a 75% reduction by 2050 • However vaccination will have minimal impact on the number of people with chronic HBV infection in Australia, which under intermediate migration projections will reach 174,000 in 2015 and 191,000 in 2025 8000 6000 4000 2000 Incident HBV infection – no vaccination Incident HBV infection – current vaccination Chronic HBV infection – no vaccination Chronic HBV infection – current vaccination EASL 2011
Proportion of people living with CHB who have not been diagnosed
Treatment uptake for CHB in Australia~ 3% as of November 2011 (preliminary)
Disease progression in HBV Fattovich 2008
Increasing evidence for HBV antiviral therapy as cancer prevention strategy • Papatheodoridis 2010 • SR of 21 studies • 3881 treated, 534 untreated • 19 LAM, 1 ADV, 1 FTC • HCC diagnosed in 2.8% treated vs6.4%untreated (p=0.003), median follow up 4 years • Also significant difference in treated patients between those with virological control and those with non-response or breakthrough likely even better prevention outcomes with new therapies
Preliminary modelling of treatment impact on annual CHB mortality to 2020
Uptake of ART for CHB by Medicare Local Credit for this analysis and content: Dr Nicole Allard, University of Melbourne 2012
Anti-cancer programs in AustraliaCost effectiveness Incremental cost effectiveness ratios per QALY: • Breast cancer screening $10,000 • Colorectal cancer screening $20,000 • Cervical cancer screening $45,000 • HCC prevention in CHB • Incorporating HCC surveillance, routine 6 monthly monitoring, referral for specialist management and treatment if ALT > 1.5x ULN $13,000
Conclusions • Conservative estimate: only 1/5 Australians needing treatment for HBV to prevent cirrhosis, cancer and death are receiving it • Liver cancer is the equal fastest increasing cause of cancer death in Australia • Antiviral treatment for CHB is effective, and cost effective • Substantial work needed to increase access to treatment and care • Treatment targets – what, by when? Acknowledgements Nicole Allard, Jennifer MacLachlan WHO Regional Reference Laboratory for Hepatitis B, VIDRL, Melbourne