Community-based screening and treatment for chronic hepatitis B in sub-Saharan Africa – Authors' reply
Authors: Shevanthi Nayagam, Lesong Conteh, Elisa Sicuri, Yusuke Shimakawa, Maud Lemoine, Timothy B Hallett, Mark Thursz
Journal: The Lancet Global Health (2016)

We thank Gang Qin and Jian-Guo Shao for their interest in our study1Nayagam S Conteh L Sicuri E et al.Cost-effectiveness of community-based screening and treatment for chronic hepatitis B in The Gambia: an economic modelling analysis.Lancet Glob Health. 2016; 4: e568-e578Summary Full Text Full Text PDF PubMed Scopus (61) Google Scholar and their observations. First, in response to their point about the baseline proportion of people in each health state, we would like to draw their attention to the table in the supplementary appendix, where these values are presented. Second, regarding the parameterisation of the natural history model, it is important to recognise that a limitation of any hepatitis B virus model is the difficulty in capturing all the heterogeneity with regards to the natural history. We chose to include only the most salient features, and accordingly some simplifying assumptions were necessary. We accept that bidirectional transitions between health states are sometimes seen in clinical practice; however, this observation is rare and there is a paucity of data to parameterise these transition rates with much accuracy. We therefore chose to exclude this feature from the model. It has been shown that there is an ongoing risk of development of hepatocellular carcinoma, even if hepatitis B virus is successfully suppressed, at least for the first few years of treatment.2Wong GL Chan HL Mak CW et al.Entecavir treatment reduces hepatic events and deaths in chronic hepatitis B patients with liver cirrhosis.Hepatology. 2013; 58: 1537-1547Crossref PubMed Scopus (357) Google Scholar, 3Lampertico P Soffredini R Yurdaydin C et al.Four years of tenofovir monotherapy for NUC naïve field practice European patients suppresses HBV replication in most patients with a favorable renal safety profile but does not prevent HCC in patients with or without cirrhosis.Dig Liver Dis. 2014; 46: e14Summary Full Text Full Text PDF Google Scholar Papatheodoridis and colleagues4Papatheodoridis GV Lampertico P Manolakopoulos S Lok A Incidence of hepatocellular carcinoma in chronic hepatitis B patients receiving nucleos(t)ide therapy: a systematic review.J Hepatol. 2010; 53: 348-356Summary Full Text Full Text PDF PubMed Scopus (370) Google Scholar showed that hepatocellular carcinoma developed in 1·2% of entecavir-treated patients early into treatment (at a median age of 1·5 years). However, this risk of development was seen particularly in older people, in men, and in those with established cirrhosis. We have therefore assumed that, if patients are non-cirrhotic at initiation of antiviral therapy and fully adherent to medications, there is no risk of progression to cirrhosis and hepatocellular carcinoma. We agree with the comment by Qin and Shao that the evidence is accumulating for the regression of fibrosis on long-term nucleos(t)ide antiviral therapy for hepatitis B virus.2Wong GL Chan HL Mak CW et al.Entecavir treatment reduces hepatic events and deaths in chronic hepatitis B patients with liver cirrhosis.Hepatology. 2013; 58: 1537-1547Crossref PubMed Scopus (357) Google Scholar, 5Marcellin P Gane E Buti M et al.Regression of cirrhosis during treatment with tenofovir disoproxil fumarate for chronic hepatitis B: a 5-year open-label follow-up study.Lancet. 2013; 381: 468-475Summary Full Text Full Text PDF PubMed Scopus (1225) Google Scholar We acknowledge that by not including the regression of fibrosis in our model, our estimate of cost-effectiveness might be slightly conservative. Finally, we understand how the labels in the tornado diagram might be misleading, and as Qin and Shao rightly point out, for these particular parameters of adherence and natural history, the higher range corresponds with the lower incremental cost-effectiveness ratio result. We declare no competing interests. Community-based screening and treatment for chronic hepatitis B in sub-Saharan AfricaShevanthi Nayagam and colleagues (August, 2016)1 estimate the cost-effectiveness of a community-based screen-and-treat programme for chronic hepatitis B in The Gambia. We have some comments on several aspects of the economic modelling. Full-Text PDF Open AccessCost-effectiveness of community-based screening and treatment for chronic hepatitis B in The Gambia: an economic modelling analysisAdult community-based screening and treatment for HBV in The Gambia is likely to be a cost-effective intervention. Higher cost-effectiveness might be achievable with targeted facility-based screening, price reductions of drugs and diagnostics, and integration of HBV screening with other public health interventions. Full-Text PDF Open Access