title: Peering into the literature: A systematic review of the roles of people who inject drugs in harm reduction initiatives.
abstract: BACKGROUND
  People who inject drugs have been central to the development of harm reduction initiatives. Referred to as peer workers, peer helpers, or natural helpers, people with lived experience of drug use leverage their personal knowledge and skills to deliver harm reduction services. Addressing a gap in the literature, this systematic review focuses on the roles of people who inject drugs in harm reduction initiatives, how programs are organized, and obstacles and facilitators to engaging people with lived experience in harm reduction programs, in order to inform practice and future research.
  
  
  METHODS
  This systematic review included searches for both peer reviewed and gray literature. All titles and abstracts were screened by two reviewers. A structured data extraction tool was developed and utilized to systematically code information concerning peer roles and participation, program characteristics, obstacles, and facilitators.
  
  
  RESULTS
  On the basis of specific inclusion criteria 164 documents were selected, with 127 peer-reviewed and 37 gray literature references. Data extraction identified key harm reduction program characteristics and forms of participation including 36 peer roles grouped into five categories, as well as obstacles and facilitators at systemic, organizational, and individual levels.
  
  
  CONCLUSIONS
  Research on harm reduction programs that involve people with lived experience can help us better understand these approaches and demonstrate their value. Current evidence provides good descriptive content but the field lacks agreed-upon approaches to documenting the ways peer workers contribute to harm reduction initiatives. Implications and ten strategies to better support peer involvement in harm reduction programs are identified.
authors.affiliation: Division of Community Health and Humanities, Faculty of Medicine, Memorial University, Health Sciences Centre, 300 Prince Philip Drive, St. John's, NL, Canada A1B 3V6. Electronic address: marshall.zack@gmail.com.
authors.forename: Z
authors.initials: Z
authors.lastname: Marshall
authors.affiliation: Department of Anthropology and Sociology, Cape Breton University, PO Box 5300, 1250 Grand Lake Road, Sydney, NS, Canada B1P 6L2. Electronic address: margaret_dechman@cbu.ca.
authors.forename: M K
authors.initials: MK
authors.lastname: Dechman
authors.affiliation: Department of Anthropology and Sociology, Cape Breton University, PO Box 5300, 1250 Grand Lake Road, Sydney, NS, Canada B1P 6L2. Electronic address: alexa.minichiello@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Minichiello
authors.affiliation: Health Sciences Library, Memorial University, St John's, NL, Canada A1B 3V6. Electronic address: lalcock@mun.ca.
authors.forename: L
authors.initials: L
authors.lastname: Alcock
authors.affiliation: Faculty of Education, G. A. Hickman Building, Memorial University, St. John's, NL, Canada A1B 3X8. Electronic address: gharris@mun.ca.
authors.forename: G E
authors.initials: GE
authors.lastname: Harris
mesh_terms: D040261:Harm Reduction; D006801:Humans; D000067074:Peer Influence; D015397:Program Evaluation; D012380:Role; D015819:Substance Abuse, Intravenous; D019966:Substance-Related Disorders / Q000534:rehabilitation*
keywords: HIV; Harm reduction; Injection drug use; Participation; Peer worker; Systematic review