Estimating the attributable fraction of cirrhosis and hepatocellular carcinoma due to hepatitis B and C.

A goal of the WHO strategy on the elimination of hepatitis as a public threat is a 65% reduction in the attributable mortality. Deaths related to hepatitis B and C infections are mostly due to decompensated cirrhosis and hepatocellular carcinoma (HCC) but accurately measuring mortality is challenging as death certificates often do not capture the underlying disease. The aim of this collaborative study between European Centre for Disease Prevention and Control (ECDC) and the European Association for the Study of the Liver (EASL) was to assess a WHO-developed protocol to support countries in implementing studies to collect data on the fraction of cirrhosis and hepatocellular carcinoma attributable to hepatitis B and C. Three sentinel sites (in Bulgaria, Norway and Portugal) collected data for patients first admitted or seen in their centres during 2016. Patients with cirrhosis or HCC were identified through patient files or healthcare databases using ICD-10 codes. The proportion of patients with cirrhosis and HCC who tested positive for HBV and HCV were calculated to estimate the aetiological fractions. After the pilot study was completed, each site was asked about the feasibility and acceptability of the protocol. A total of 1249 patients presenting with cirrhosis and/or HCC were evaluated across the three sites. The prevalence of HBV and HCV among cases of cirrhosis showed that in Norway and Portugal, HCV was responsible for about one-quarter of the cases, whereas in Bulgaria, HBV was more common. For HCC, HCV was responsible for more than one-third of cases in Norway and Portugal, while in Bulgaria HBV was more frequent as the underlying cause. Results obtained during the pilot study were comparable to published estimates obtained through statistical modelling or meta-analyses. Several challenges were reported from the sites involved in the pilot including the considerable time needed for reviewing the hospital records and extracting patient data. The pilot demonstrated the feasibility of collecting data on the prevalence of HBV and HCV infection among patients with cirrhosis and HCC in sentinel sites. This method can be used to estimate mortality attributable to HBV and HCV for elimination monitoring. Where easily implementable, sentinel studies are the best way to empower countries, get up-to date data and closely monitor the changes in the attributable fraction at a country level.

Mortality from liver diseases attributable to hepatitis B and C in the EU/EEA - descriptive analysis and estimation of 2015 baseline.

Background: WHO has set target to reduce mortality attributable to hepatitis B (HBV) and hepatitis C (HCV) by 65% by 2030, with 2015 as baseline. We aimed to describe the European Union/European Economic Area (EU/EEA) baseline mortality from liver diseases, as defined by WHO Core-10 indicator through ICD-10 codes, and estimate mortality attributable to HBV and HCV.Methods: Age-standardised mortality rates per 100,000 for hepatocellular carcinoma (HCC, ICD-10 C22.0), chronic liver disease (CLD, ICD-10 K72-K75) and chronic viral hepatitis B and C (CHB/CHC, ICD-10 B18.1-B18.3) were calculated by gender, age-group and country using 2015 Eurostat data. Because aetiology fraction (AF) estimates were lacking for HCC and CLD as defined by C10, number of deaths in EU/EEA countries in 2015 from liver cancer (ICD-10 C22) and 'cirrhosis and other chronic liver diseases' (ICD-10 B18-B18.9, I85-I85.9, I98.2, K70-K70.3, K71.7, K74-K74.9, K75.2, K75.4-K76.2, K76.4-K76.9 and K77.8) were adjusted by corresponding AF estimates from Global Burden of Disease publications.Results: In 2015, there were wide variations across countries in mortality rates from HCC, CLD and CHB/CHC. A 2015 mortality baseline of 63,927 deaths attributable to HBV and HCV is proposed, that includes 55% of liver cancer and 45% of 'cirrhosis and other chronic liver diseases' deaths.Conclusions: The HBV and HCV attributable mortality in the EU/EEA is high. Greater efforts are needed to identify HBV and HCV infections at an early stage and link cases to care to reduce mortality from liver diseases. Country-specific AF estimates are needed to accurately estimate HBV, HCV associated mortality.