title: A socio-structural approach to preventing injection drug use initiation: rationale for the PRIMER study.
abstract: Injection drug use remains a primary driver of HIV and HCV-related harms globally. However, there is a gap in efforts to prevent individuals from transitioning into injecting. People who inject drugs (PWID) play a key role in the transition of others into injecting, and while behavioral interventions have been developed to address this phenomenon, socio-structural approaches remain unexplored. To that end, we hypothesize that certain interventions designed to reduce injecting-related risk behaviors may also reduce the risk that PWID expose and introduce others into injecting. Identifying the preventive potential of existing interventions will inform broader efforts to prevent injecting and related harms.
  
  
  
  The Preventing Injecting by Modifying Existing Responses (PRIMER) study is a multi-country mixed methods study with an aim to investigate whether specific interventions (e.g., opioid substitution therapy, supervised injection facilities, stable housing, incarceration environments) and related factors (e.g., public injecting and gender) influence the likelihood that PWID initiate others into injecting. This study will (1) investigate the PWID participation in injection initiation; (2) identify factors influencing the risk that PWID expose others to or facilitate injection initiation; (3) describe drug scene roles that increase the risk of PWID facilitating injection initiation; and (4) evaluate the impact of structural, social, or biomedical interventions on the risk that PWID facilitate injection initiation. It does so by pooling observational data from cohort studies of PWID in six cities: Vancouver, Canada; San Diego, USA; Tijuana, Mexico; Paris, Marseille, and Bordeaux, France.
  
  
  
  Team members are conducting a prospective, multi-site study of PWID (n = 3050) in North America and France that includes quantitative and qualitative data collection through four separate cohort studies of PWID (San Diego, STAHR II; Tijuana, El Cuete IV; Vancouver, V-DUS; Bordeaux, Marseille, Paris and Strasbourg, COSINUS).
  
  
  
  PRIMER is the largest study of injection initiation to date and the first to investigate structural approaches to preventing injection drug use initiation. Findings have the potential to inform the development and scale up of new and existing interventions to prevent transitions into injecting.
  
  
  
  Preventing Injecting by Modifying Existing Responses (PRIMER), NIDA DP2-DA040256-01 .
authors.affiliation: Division of Global Public Health, Department of Medicine, University of California San Diego, San Diego, USA. dwerb@ucsd.edu.|Division of Global Public Health, University of California School of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0507, USA. dwerb@ucsd.edu.
authors.forename: Daniel
authors.identifier: 0000-0003-0614-9386
authors.initials: D
authors.lastname: Werb
authors.affiliation: Division of Global Public Health, Department of Medicine, University of California San Diego, San Diego, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Garfein
authors.affiliation: Urban Health Research Initiative, British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kerr
authors.affiliation: Division of Global Public Health, Department of Medicine, University of California San Diego, San Diego, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Davidson
authors.affiliation: INSERM, UMR_S 912, Sciences Economiques & Sociales de la Santé et Traitement de l'Information Médicale (SESSTIM), F-13385, Marseille, France.
authors.forename: Perrine
authors.initials: P
authors.lastname: Roux
authors.affiliation: Inserm U988/CNRS UMR 8211, Ecole des Hautes Etudes en Sciences Sociales, Université de Paris Descartes, Paris, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Jauffret-Roustide
authors.affiliation: SANSPY/CNRS USR 3413, Université de Bordeaux, Bordeaux, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Auriacombe
authors.affiliation: Urban Health Research Initiative, British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada.
authors.forename: Will
authors.initials: W
authors.lastname: Small
authors.affiliation: Division of Global Public Health, Department of Medicine, University of California San Diego, San Diego, USA.
authors.forename: Steffanie A
authors.initials: SA
authors.lastname: Strathdee
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D005260:Female; D015658:HIV Infections / Q000517:prevention & control / Q000635:transmission; D006526:Hepatitis C / Q000517:prevention & control / Q000635:transmission; D006703:Ill-Housed Persons / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D016485:Needle Sharing / Q000706:statistics & numerical data; D018671:Needle-Exchange Programs / Q000706:statistics & numerical data; D011446:Prospective Studies; D012309:Risk-Taking; D015819:Substance Abuse, Intravenous / Q000517:prevention & control*; D055815:Young Adult
keywords: HIV prevention; Injection initiation; Multi-site study; Natural history of injecting; People who inject drugs; Street youth