Increasing prevalence of chronic hepatitis B virus infection and low linkage to care in Denmark on 31 December 2016 – an update based on nationwide registers

Abstract

Objectives

We aimed to update the estimated prevalence of both diagnosed and undiagnosed chronic hepatitis B virus infection in Denmark. Moreover, we aimed to determine the number of people with chronic hepatitis B virus infection in specialised care and to assess the completeness of reporting to the national register of communicable diseases.

Methods

Using four registers with national coverage, we identified all individuals registered with chronic hepatitis B virus infection, aged 16 years or older, and alive in Denmark on 31 December 2016. The diagnosed population was then estimated using capture-recapture analysis. The undiagnosed population was estimated using data from the Danish pregnancy screening program.

Results

We estimated that 14,548 individuals were living with chronic hepatitis B virus infection corresponding to 0.3% of the Danish population. Of them, 13,530 (93%) were diagnosed and 7942 (55%) were registered in one or more of the source registers. Only 4297 (32%) diagnosed individuals had attended specialised care and only 3289 cases (24%) were reported to the Danish communicable disease register.

Conclusion

The prevalence of chronic hepatitis B virus infection increased from 2007 to 2017. The majority that had been diagnosed did not receive care as recommended by national guidelines and were not reported to the communicable diseases register responsible for hepatitis B virus surveillance. Future efforts should focus on linking individuals diagnosed with chronic hepatitis B virus infection to specialised care and improving reporting to the hepatitis B virus surveillance system.

Keywords:

• Prevalence
• chronic hepatitis B virus infection
• Denmark
• capture-recapture

Acknowledgements

We thank all patients registered in DANHEP for providing data for this study and members of the DANHEP group: Alex Lund Laursen; Birgit Thorup Røge; Britta Tarp; Jan Gerstoft; Jesper Bach Hansen; Lise Hobolth; Lone Galmstrup Madsen; Lone Mygind; Mette Rye Clausen; Peter Thielsen; Toke Barfod and Ulla Balslev for their contribution with data registering.

Ethical approval

The study was approved by the Danish Data Protection Agency (Journal no: 16/43190 and 18/52996). No further approvals were necessary for register-based studies according to Danish law.

Authors contributions

Signe Bollerup contributed with data management, methodological decisions, interpretation of results and writing of the manuscript. Maria Wessman assisted with study design, data management, methodological decisions and review and editing of the manuscript. Janne Fuglsang Hansen assisted with data acquisition, data management, review and editing of the manuscript. Stine Nielsen contributed to study design and review and editing of the manuscript. Gordon Hay performed the statistical analysis, assisted with methodological decisions and reviewed and edited the manuscript. Susan Cowan, Henrik Krarup, Lars Omland, Peter Jepsen and Nina Weis provided data and reviewed and edited the manuscript. Peer Brehm Christensen managed the project, and contributed to the study design, data acquisition, methodological decisions, interpretation of results, manuscript production and editing.

Disclosure statement

Peer Brehm Christensen has received grants not related to this study from Abbvie, Gilead and MSD. Nina Weis has been a clinical investigator, lecturer or member of advisory boards for Abbvie, Gilead, GSK and MSD and have received unrestricted grants for research from Abbvie, Gilead and the Novo Nordisk Foundation with no relation to the present work. Signe Bollerup received support for conference participation from Abbvie, Gilead and MSD. The remaining authors had no financial interests to disclose.

Data availability statement

The dataset for the study is available from Zenodo.org. DOI: 10.5281/zenodo.5824584.

Additional information

Funding

Signe Bollerup: Manufacturer Vilhelm Pedersen and Wifés Foundation, URL: https://vplegat.dk/; Free research funds of University Hospital of Copenhagen, Amager and Hvidovre, URL: https://www.hvidovrehospital.dk/forskning/Sider/default.aspx; Scholarship in Memory of Carpenter Jørgen Holm and wife Elisa B. Hansen [20006-1948], URL: https://www.holmsmindelegat.dk/; Aase and Ejnar Danielsens Foundation, URL: https://danielsensfond.dk/; Scandinavian Society for Antimicrobial Chemotherapy Foundation [SLS-935536], URL: https://www.nscmid.org/what-we-do/grants/171-grant1. Data extraction, cleaning and statistical support for the study were financed by an unrestricted grant from Merck Sharpe & Dohme (MSD) Denmark, URL: https://www.msd.dk/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.