title: HCV treatment uptake in people who have injected drugs - observations in a large cohort that received addiction treatment 1970-1984.
abstract: OBJECTIVE
  The aim of this study was to document antiviral treatment uptake among former or current people who inject drugs (PWID) with chronic hepatitis C and to explore a possible association between treatment and mortality.
  
  
  METHODS
  This is a longitudinal cohort study of PWID admitted for drug abuse treatment 1970-1984. The 245 hepatitis C virus (HCV) RNA-positive patients alive by the end of 1996 were followed 1997-2012 through linkage to several health registers. Treatment uptake was mainly documented by information on prescription of antiviral medication registered in the Norwegian Prescription Database from 2004. Cox regression, with a time-dependent covariate measuring end-of-treatment, was employed to evaluate mortality after treatment.
  
  
  RESULTS
  At the end of the follow-up, median time since HCV exposure was 36 years, and 19.2% (47/245) had been prescribed antiviral treatment for chronic HCV infection. No gender difference was observed. Among those alive at the end of the study period, 27.8% (44/158) had been treated. Relative hazard of death was 0.21 (95% confidence interval [CI] 0.07-0.68), comparing periods for patients after versus before or without treatment. Mortality rate after treatment was 0.8 per 100 person years (95% CI 0.3-2.4) compared to 2.8 (95% CI 2.2-3.5) in untreated patients and before treatment. The most important causes of death among the untreated were drug-related.
  
  
  CONCLUSIONS
  Among PWID infected with HCV, approximately one-fourth of those still alive at a median of 36 years after exposure had received HCV treatment. Treatment was associated with increased survival, probably mainly due to selection bias.
authors.affiliation: National Centre for Dual Diagnosis, Innlandet Hospital Trust , Brumunddal , Norway.
authors.forename: Knut Boe
authors.initials: KB
authors.lastname: Kielland
authors.forename: Ellen J
authors.initials: EJ
authors.lastname: Amundsen
authors.forename: Olav
authors.initials: O
authors.lastname: Dalgard
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use*; D005260:Female; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000209:etiology / Q000401:mortality; D006801:Humans; D007275:Injections, Intravenous; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D019966:Substance-Related Disorders / Q000150:complications* / Q000628:therapy; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents
keywords: CHC; HCV; drug therapy; hepatitis C; substance use; substance-related disorders; treatment uptake