title: Epidemiology of hepatitis C virus infection among people receiving opioid substitution therapy (ECHO): study protocol.
abstract: BACKGROUND
  Hepatitis C virus infection is highly prevalent among people who inject drugs. Opioid substitution therapy, the standard treatment for opioid dependence, provides an excellent opportunity for the treatment of hepatitis C virus infection due to the close and regular contact between patients and clinicians. However, there is little research on the impact of opioid substitution therapy on the prevalence of the hepatitis C virus at a national level. This paper describes the protocol for the Epidemiology of Hepatitis C Virus Infection among People Receiving Opioid Substitution Therapy (ECHO) study. The aim of this study is to estimate the national prevalence and incidence of hepatitis C virus infection among people receiving opioid substitution therapy in Germany and to describe factors associated with hepatitis C treatment uptake and seroconversion.
  
  
  METHODS
  An observational, longitudinal, multicentre study is being conducted between 2014 and 2016 in a representative sample of approximately 2500 people receiving opioid substitution therapy from about 100 clinicians providing opioid substitution therapy in Germany. Data will be collected during routine patient care and by means of patient and clinician questionnaires at baseline and 12-month follow-up. Stratified sampling will be performed to obtain a representative sample of clinicians providing opioid substitution therapy. The strata will be constructed based on the distribution of the total sample of clinicians providing opioid substitution therapy in Germany according to German Federal State and the number of patients per clinician.
  
  
  CONCLUSIONS
  Opioid substitution therapy may be an important strategy to prevent the spread of hepatitis C virus in opioid dependent populations, but its effectiveness may be diminished by our limited understanding of factors associated with treatment uptake and seroconversion. The present study will provide important information for developing strategies to address hepatitis C virus-related disease burden in people receiving opioid substitution therapy.
  
  
  BACKGROUND
  ClinicalTrials.gov: NCT02395198.
authors.affiliation: Centre for Interdisciplinary Addiction Research, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany. l.strada@uke.de.
authors.forename: Lisa
authors.initials: L
authors.lastname: Strada
authors.affiliation: Centre for Interdisciplinary Addiction Research, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany. b.schulte@uke.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Schulte
authors.affiliation: Centre for Interdisciplinary Addiction Research, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany. christiane.schmidt@uke.de.
authors.forename: Christiane Sybille
authors.initials: CS
authors.lastname: Schmidt
authors.affiliation: Centre for Interdisciplinary Addiction Research, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany. u.verthein@uke.de.
authors.forename: Uwe
authors.initials: U
authors.lastname: Verthein
authors.affiliation: Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany. Peter.Cremer-Schaeffer@bfarm.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Cremer-Schaeffer
authors.affiliation: Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany. Sabine.Krueckeberg@bfarm.de.
authors.forename: Sabine
authors.initials: S
authors.lastname: Krückeberg
authors.affiliation: Centre for Interdisciplinary Addiction Research, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany. reimer@uke.de.
authors.forename: Jens
authors.initials: J
authors.lastname: Reimer
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use; D005260:Female; D005838:Genotype; D005858:Germany / Q000453:epidemiology; D016174:Hepacivirus / Q000235:genetics; D006526:Hepatitis C / Q000453:epidemiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D058850:Opiate Substitution Treatment; D015995:Prevalence; D015819:Substance Abuse, Intravenous / Q000150:complications
chemical_list: D000701:Analgesics, Opioid