title: Hepatitis C Virus seroconversion among persons who inject drugs in relation to primary care physician visiting: The potential role of primary healthcare in a combined approach to Hepatitis C prevention.
abstract: BACKGROUND
  Meaningful reductions in Hepatitis C Virus (HCV) transmission rates among persons who inject drugs (PWID) require a comprehensive prevention approach, including access to harm reduction measures and to healthcare-related interventions, such as HCV screening, testing and antiviral treatment. Little is known, however, about the role of visiting a primary care physician (PCP) in relation to HCV infection risk among PWID, when integrated within a combined prevention approach. This study assessed the association between PCP visiting and HCV seroconversion among PWID attending needle exchange programs (NEP).
  
  
  METHODS
  A prospective cohort study, HEPCO, was conducted among active PWID in Montréal (2004-2013). Interviews scheduled at 3- or 6-month intervals included completion of an interviewer-administered questionnaire, and collection of blood samples for HCV antibody testing. HCV-seronegative participants who reported NEP attendance at baseline and had at least one follow-up visit were eligible for this study. HCV incidence was calculated using the person-time method. Time-varying Cox regression modeling was conducted to evaluate the relationship between self-reported recent PCP visiting and HCV incidence.
  
  
  RESULTS
  At baseline assessment, of 226 participants (80.5% male; median age: 30.6 years), 37.2% reported having recently visited a PCP. During 449.6 person-years of follow-up, 79 participants seroconverted to HCV [incidence rate: 17.6 per 100 person-years, 95% confidence interval (CI): 14.0-21.8]. Covariate-adjusted analyses indicated that visiting a PCP was associated with a lower risk of HCV infection [Adjusted Hazard Ratio: 0.54, 95% CI: 0.31-0.93]. Other independent predictors of HCV infection included unstable housing, cocaine injection and prescription opioid injection.
  
  
  CONCLUSIONS
  Among PWID attending NEP, visiting a PCP was associated with a lower risk of HCV infection. Yet, only a minority of participants reported PCP visiting. Efforts to intensify engagement with PCP among PWID could potentially contribute to lower HCV transmission when integrated within a combined approach to prevention.
authors.affiliation: Research Center, Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint-Denis, Montréal, QC, Canada H2X 0A9; Department of Family Medicine, Faculty of Medicine, McGill University, 5858 Chemin de la Côte-des-Neiges, Montréal, QC, Canada H3S 1Z1.
authors.forename: Andreea Adelina
authors.initials: AA
authors.lastname: Artenie
authors.affiliation: Addiction Research and Study Program, Faculty of Medicine and Health Sciences, Université de Sherbrooke, 150 Place Charles-Le Moyne, Longueuil, QC, Canada J4K 0A8; Institut National de Santé Publique du Québec, 190 Crémazie E, Montréal, QC, Canada H2P 1E2.
authors.forename: Élise
authors.initials: É
authors.lastname: Roy
authors.affiliation: Research Center, Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint-Denis, Montréal, QC, Canada H2X 0A9.
authors.forename: Geng
authors.initials: G
authors.lastname: Zang
authors.affiliation: Research Center, Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint-Denis, Montréal, QC, Canada H2X 0A9; Department of Psychiatry, Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC, Canada H3C 3J7.
authors.forename: Didier
authors.initials: D
authors.lastname: Jutras-Aswad
authors.affiliation: Research Center, Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint-Denis, Montréal, QC, Canada H2X 0A9.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Bamvita
authors.affiliation: Research Center, Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint-Denis, Montréal, QC, Canada H2X 0A9; Department of Family Medicine, Faculty of Medicine, McGill University, 5858 Chemin de la Côte-des-Neiges, Montréal, QC, Canada H3S 1Z1.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Puzhko
authors.affiliation: School of Population Health, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia; Department of Medicine, St. Vincent's Hospital, The University of Melbourne, 29 Regent Street, Fitzroy, VIC 3065, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Daniel
authors.affiliation: Research Center, Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint-Denis, Montréal, QC, Canada H2X 0A9; Department of Family Medicine, Faculty of Medicine, McGill University, 5858 Chemin de la Côte-des-Neiges, Montréal, QC, Canada H3S 1Z1; Department of Family and Emergency Medicine, Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, QC, Canada H3C 3J7. Electronic address: julie.bruneau@umontreal.ca.
authors.forename: Julie
authors.initials: J
authors.lastname: Bruneau
mesh_terms: D000328:Adult; D005260:Female; D016174:Hepacivirus / Q000276:immunology*; D006526:Hepatitis C / Q000453:epidemiology / Q000276:immunology* / Q000517:prevention & control* / Q000635:transmission; D006801:Humans; D008297:Male; D018671:Needle-Exchange Programs; D011320:Primary Health Care; D011446:Prospective Studies; D011792:Quebec / Q000453:epidemiology; D000069078:Seroconversion; D015819:Substance Abuse, Intravenous / Q000453:epidemiology* / Q000276:immunology
keywords: Drug use; Hepatitis C; Injection; Physician; Prevention; Primary care