Peering into the literature: A systematic review of the roles of people who inject drugs in harm reduction initiatives.
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. 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. 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. 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.