title: Evidence of continued injecting drug use after attaining sustained treatment-induced clearance of the hepatitis C virus: Implications for reinfection.
abstract: BACKGROUND
  People who inject drugs (PWID) are at the greatest risk of hepatitis C virus (HCV) infection, yet are often denied immediate treatment due to fears of on-going risk behaviour. Our principal objective was to examine evidence of continued injecting drug use among PWID following successful treatment for HCV and attainment of a sustained viral response (SVR).
  
  
  METHODS
  PWID who attained SVR between 1992 and June 2012 were selected from the National Scottish Hepatitis C Clinical Database. Hospitalisation and mortality records were sourced for these patients using record linkage techniques. Our primary outcome variable was any hospitalisation or death, which was indicative of injecting drugs post-SVR.
  
  
  RESULTS
  The cohort comprised 1170 PWID (mean age at SVR 39.6y; 76% male). The Kaplan Meier estimate of incurring the primary outcome after three years of SVR was 10.59% (95% CI, 8.75-12.79) After adjusting for confounding, the risk of an injection related hospital episode or death post-SVR was significantly increased with advancing year of SVR: AHR:1.07 per year (95% CI, 1.01-1.14), having a pre-SVR acute alcohol intoxication-related hospital episode: AHR:1.83 (95% CI, 1.29-2.60), and having a pre-SVR opiate or injection-related hospital episode: AHR:2.59 (95% CI, 1.84-3.64).
  
  
  CONCLUSIONS
  Despite attaining the optimal treatment outcome, these data indicate that an increasing significant minority of PWID continue to inject post-SVR at an intensity which leads to either hospitalisation or death and increased risk of reinfection.
authors.affiliation: School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Blood-borne Viruses and Sexually Transmitted Infections Section, Health Protection Scotland, Glasgow, UK. Electronic address: Heather.valerio@nhs.net.
authors.forename: Heather
authors.initials: H
authors.lastname: Valerio
authors.affiliation: Blood-borne Viruses and Sexually Transmitted Infections Section, Health Protection Scotland, Glasgow, UK; School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Goldberg
authors.affiliation: Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK.
authors.forename: James
authors.initials: J
authors.lastname: Lewsey
authors.affiliation: School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Blood-borne Viruses and Sexually Transmitted Infections Section, Health Protection Scotland, Glasgow, UK.
authors.forename: Amanda
authors.initials: A
authors.lastname: Weir
authors.affiliation: Crosshouse Hospital, Kilmarnock, UK.
authors.forename: Samuel
authors.initials: S
authors.lastname: Allen
authors.affiliation: School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Blood-borne Viruses and Sexually Transmitted Infections Section, Health Protection Scotland, Glasgow, UK.
authors.forename: Esther J
authors.initials: EJ
authors.lastname: Aspinall
authors.affiliation: Glasgow Royal Infirmary, Glasgow, UK.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Barclay
authors.affiliation: Stirling Community Hospital, Stirling, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Bramley
authors.affiliation: Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: John F
authors.initials: JF
authors.lastname: Dillon
authors.affiliation: Gartnavel General Hospital, Glasgow, UK.
authors.forename: Ray
authors.initials: R
authors.lastname: Fox
authors.affiliation: Aberdeen Royal Infirmary, Aberdeen, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Fraser
authors.affiliation: Royal Infirmary Edinburgh, Edinburgh, UK.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Hayes
authors.affiliation: School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Blood-borne Viruses and Sexually Transmitted Infections Section, Health Protection Scotland, Glasgow, UK.
authors.forename: Hamish
authors.initials: H
authors.lastname: Innes
authors.affiliation: Monklands Hospital, Lanarkshire, UK.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Kennedy
authors.affiliation: Gartnavel General Hospital, Glasgow, UK.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Mills
authors.affiliation: Glasgow Royal Infirmary, Glasgow, UK.
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Stanley
authors.affiliation: School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK; Blood-borne Viruses and Sexually Transmitted Infections Section, Health Protection Scotland, Glasgow, UK.
authors.forename: Sharon J
authors.initials: SJ
authors.lastname: Hutchinson
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006526:Hepatitis C / Q000150:complications / Q000453:epidemiology* / Q000401:mortality; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012606:Scotland / Q000453:epidemiology; D015819:Substance Abuse, Intravenous / Q000150:complications / Q000453:epidemiology*; D016896:Treatment Outcome; D055815:Young Adult
keywords: Hepatitis C; People who inject drugs; Record linkage; Reinfection; Sustained viral response