title: Treatment for hepatitis C virus infection among people who inject drugs attending opioid substitution treatment and community health clinics: the ETHOS Study.
abstract: OBJECTIVE
  To estimate adherence and response to therapy for chronic hepatitis C virus (HCV) infection among people with a history of injecting drug use. A secondary aim was to identify predictors of HCV treatment response.
  
  
  METHODS
  Prospective cohort recruited between 2009 and 2012. Participants were treated with peg-interferon alfa-2a/ribavirin for 24 (genotypes 2/3, G2/3) or 48 weeks (genotype 1, G1).
  
  
  METHODS
  Six opioid substitution treatment (OST) clinics, two community health centres and one Aboriginal community-controlled health organization providing drug treatment services in New South Wales, Australia.
  
  
  METHODS
  Among 415 people with a history of injecting drug use and chronic HCV assessed by a nurse, 101 were assessed for treatment outcomes (21% female).
  
  
  METHODS
  Study outcomes were treatment adherence and sustained virological response (SVR, undetectable HCV RNA >24 weeks post-treatment).
  
  
  RESULTS
  Among 101 treated, 37% (n = 37) had recently injected drugs (past 6 months) and 62% (n = 63) were receiving OST. Adherence ≥ 80% was 86% (n = 87). SVR was 74% (75 of 101), with no difference observed by sex (males: 76%, females: 67%, P = 0.662). In adjusted analysis, age < 35 (versus ≥ 45 years) [adjusted odds ratio (aOR) = 5.06, 95% confidence interval (CI) = 1.47, 17.40] and on-treatment adherence ≥ 80% independently predicted SVR (aOR = 19.41, 95% CI = 3.61, 104.26]. Recent injecting drug use at baseline was not associated with SVR.
  
  
  CONCLUSIONS
  People with a history of injecting drug use and chronic hepatitis C virus attending opioid substitution treatment and community health clinics can achieve adherence and responses to interferon-based therapy similar to other populations, despite injecting drugs at baseline. Younger age and adherence are predictive of improved response to hepatitis C virus therapy.
authors.affiliation: The Kirby Institute, UNSW Australia, Sydney, NSW, Australia.
authors.forename: Jason
authors.identifier: http://orcid.org/0000-0002-1833-2017
authors.initials: J
authors.lastname: Grebely
authors.affiliation: The Kirby Institute, UNSW Australia, Sydney, NSW, Australia.
authors.forename: Maryam
authors.initials: M
authors.lastname: Alavi
authors.affiliation: The Kirby Institute, UNSW Australia, Sydney, NSW, Australia.
authors.forename: Michelle
authors.initials: M
authors.lastname: Micallef
authors.affiliation: University of Newcastle, Newcastle, NSW, Australia.|Drug and Alcohol Clinical Services, Hunter New England Local Health District, Newcastle, NSW, Australia.
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Dunlop
authors.affiliation: Clinic 96, Kite St Community Health Centre, Orange, NSW, Australia.
authors.forename: Anne C
authors.initials: AC
authors.lastname: Balcomb
authors.affiliation: Drug Health Services, Western Sydney Local Health District, NSW, Australia.
authors.forename: Nghi
authors.initials: N
authors.lastname: Phung
authors.affiliation: Gastroenterology and Hepatology, Nepean Hospital, Kingswood, NSW, Australia.|Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Martin D
authors.initials: MD
authors.lastname: Weltman
authors.affiliation: Sydney Medical School, University of Sydney, Sydney, NSW, Australia.|Drug Health Service, Royal Prince Alfred Hospital, Sydney, NSW, Australia.
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Day
authors.affiliation: Centre for Social Research in Health, UNSW Australia, Sydney, NSW, Australia.
authors.forename: Carla
authors.initials: C
authors.lastname: Treloar
authors.affiliation: NSW Health, Sydney, NSW, Australia.
authors.forename: Nicky
authors.initials: N
authors.lastname: Bath
authors.affiliation: Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Haber
authors.affiliation: The Kirby Institute, UNSW Australia, Sydney, NSW, Australia.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Dore
mesh_terms: D000328:Adult; D000368:Aged; D000553:Ambulatory Care / Q000379:methods; D000998:Antiviral Agents / Q000008:administration & dosage; D003151:Community Health Centers; D003695:Delivery of Health Care; D004359:Drug Therapy, Combination; D005260:Female; D019698:Hepatitis C, Chronic / Q000175:diagnosis / Q000188:drug therapy*; D006801:Humans; D016898:Interferon-alpha / Q000008:administration & dosage; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D009517:New South Wales; D058850:Opiate Substitution Treatment / Q000379:methods; D009293:Opioid-Related Disorders / Q000534:rehabilitation*; D011092:Polyethylene Glycols / Q000008:administration & dosage; D011994:Recombinant Proteins / Q000008:administration & dosage; D012254:Ribavirin / Q000008:administration & dosage; D016320:Substance Abuse Treatment Centers; D015819:Substance Abuse, Intravenous / Q000534:rehabilitation*; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D016898:Interferon-alpha; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D012254:Ribavirin; C100416:peginterferon alfa-2a
keywords: Antiviral therapy; hepatitis C virus; injecting drug use; methadone; opioid substitution treatment; people who inject drugs