{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T14:52:12Z","timestamp":1788187932190,"version":"build-2803163510"},"reference-count":33,"publisher":"Wiley","issue":"6","license":[{"start":{"date-parts":[[2024,3,6]],"date-time":"2024-03-06T00:00:00Z","timestamp":1709683200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000024","name":"Canadian Institutes of Health Research","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100000024","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Liver International"],"published-print":{"date-parts":[[2024,6]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background<\/jats:title><jats:p>Patients with chronic hepatitis C (CHC) can be cured with the new highly effective interferon\u2010free combination treatments (DAA) that were approved in 2014. However, CHC is a largely silent disease, and many individuals are unaware of their infections until the late stages of the disease. The impact of wider access to effective treatments and improved awareness of the disease on the number of infections and the number of patients who remain undiagnosed is not known in Canada. Such evidence can guide the development of strategies and interventions to reduce the burden of CHC and meet World Health Organization's (WHO) 2030 elimination targets. The purpose of this study is to use a back\u2010calculation framework informed by provincial population\u2010level health administrative data to estimate the prevalence of CHC and the proportion of cases that remain undiagnosed in the three most populated provinces in Canada: British Columbia (BC), Ontario and Quebec.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>We have conducted a population\u2010based retrospective analysis of health administrative data for the three provinces to generate the annual incidence of newly diagnosed CHC cases, decompensated cirrhosis (DC), hepatocellular carcinoma (HCC) and HCV treatment initiations. For each province, the data were stratified in three birth cohorts: individuals born prior to 1945, individuals born between 1945 and 1965 and individuals born after 1965. We used a back\u2010calculation modelling approach to estimate prevalence and the undiagnosed proportion of CHC. The historical prevalence of CHC was inferred through a calibration process based on a Bayesian Markov chain Monte Carlo (MCMC) algorithm. The algorithm constructs the historical prevalence of CHC for each cohort by comparing the model\u2010generated outcomes of the annual incidence of the CHC\u2010related health events against the data set of observed diagnosed cases generated in the retrospective analysis.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The results show a decreasing trend in both CHC prevalence and undiagnosed proportion in BC, Ontario and Quebec. In 2018, CHC prevalence was estimated to be 1.23% (95% CI: .96%\u20131.62%), .91% (95% CI: .82%\u20131.04%) and .57% (95% CI: .51%\u2013.64%) in BC, Ontario and Quebec respectively. The CHC undiagnosed proportion was assessed to be 35.44% (95% CI: 27.07%\u201345.83%), 34.28% (95% CI: 26.74%\u201341.62%) and 46.32% (95% CI: 37.85%\u201352.80%) in BC, Ontario and Quebec, respectively, in 2018. Also, since the introduction of new DAA treatment in 2014, CHC prevalence decreased from 1.39% to 1.23%, .97% to .91% and .65% to .57% in BC, Ontario and Quebec respectively. Similarly, the CHC undiagnosed proportion decreased from 38.78% to 35.44%, 38.70% to 34.28% and 47.54% to 46.32% in BC, Ontario and Quebec, respectively, from 2014 to 2018.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>We estimated that the CHC prevalence and undiagnosed proportion have declined for all three provinces since the new DAA treatment has been approved in 2014. Yet, our findings show that a significant proportion of HCV cases remain undiagnosed across all provinces highlighting the need to increase investment in screening. Our findings provide essential evidence to guide decisions about current and future HCV strategies and help achieve the WHO goal of eliminating hepatitis C in Canada by 2030.<\/jats:p><\/jats:sec>","DOI":"10.1111\/liv.15875","type":"journal-article","created":{"date-parts":[[2024,3,6]],"date-time":"2024-03-06T13:48:57Z","timestamp":1709732937000},"page":"1383-1395","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Impact of new direct\u2010acting antiviral therapy on the prevalence and undiagnosed proportion of chronic hepatitis C infection"],"prefix":"10.1111","volume":"44","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1833-823X","authenticated-orcid":false,"given":"Farinaz","family":"Forouzannia","sequence":"first","affiliation":[{"name":"School of Pharmacy University of Waterloo  Kitchener Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abdullah","family":"Hamadeh","sequence":"additional","affiliation":[{"name":"School of Pharmacy University of Waterloo  Kitchener Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4814-5191","authenticated-orcid":false,"given":"Ana Maria","family":"Passos\u2010Castilho","sequence":"additional","affiliation":[{"name":"Lady Davis Institute, Jewish General Hospital  Montreal Quebec Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0441-3497","authenticated-orcid":false,"given":"Aysegul","family":"Erman","sequence":"additional","affiliation":[{"name":"Toronto Health Economics and Technology Assessment Collaborative (THETA) University Health Network  Toronto Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amanda","family":"Yu","sequence":"additional","affiliation":[{"name":"British Columbia Centre for Disease Control  Vancouver British Columbia Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zeny","family":"Feng","sequence":"additional","affiliation":[{"name":"Department of Mathematics and Statistics University of Guelph  Guelph Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Naveed Z.","family":"Janjua","sequence":"additional","affiliation":[{"name":"British Columbia Centre for Disease Control  Vancouver British Columbia Canada"},{"name":"School of Population and Public Health University of British Columbia  Vancouver British Columbia Canada"},{"name":"Centre for Advancing Health Outcomes, St. Paul's Hospital  Vancouver British Columbia Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Beate","family":"Sander","sequence":"additional","affiliation":[{"name":"Toronto Health Economics and Technology Assessment Collaborative (THETA) University Health Network  Toronto Ontario Canada"},{"name":"Institute of Health Policy, Management and Evaluation University of Toronto  Toronto Ontario Canada"},{"name":"ICES  Toronto Ontario Canada"},{"name":"Public Health Ontario  Toronto Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christina","family":"Greenaway","sequence":"additional","affiliation":[{"name":"Lady Davis Institute, Jewish General Hospital  Montreal Quebec Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4630-0052","authenticated-orcid":false,"given":"William W. L.","family":"Wong","sequence":"additional","affiliation":[{"name":"School of Pharmacy University of Waterloo  Kitchener Ontario Canada"},{"name":"Toronto Health Economics and Technology Assessment Collaborative (THETA) University Health Network  Toronto Ontario Canada"},{"name":"Institute of Health Policy, Management and Evaluation University of Toronto  Toronto Ontario Canada"},{"name":"ICES  Toronto Ontario Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2024,3,6]]},"reference":[{"key":"e_1_2_14_2_1","doi-asserted-by":"publisher","DOI":"10.1503\/cmaj.170453"},{"key":"e_1_2_14_3_1","doi-asserted-by":"publisher","DOI":"10.1093\/cid\/ciy585"},{"key":"e_1_2_14_4_1","unstructured":"WHO. Accessed July 30 2023.https:\/\/www.who.int\/news\u2010room\/fact\u2010sheets\/detail\/hepatitis\u2010c"},{"key":"e_1_2_14_5_1","unstructured":"Message from the Minister of Health\u2014World Hepatitis Day.Government of Canada;2016. 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