title: Methadone maintenance therapy and viral suppression among HIV-infected opioid users: The impacts of crack and injection cocaine use.
abstract: Methadone maintenance therapy (MMT) is associated with improved HIV treatment outcomes among people who use drugs (PWUD). The extent to which these benefits are sustained in the context of ongoing cocaine use is unclear. We assessed differential impacts of MMT on HIV viral load (VL) suppression in relation to discrete patterns of cocaine use.
  
  
  
  Data was drawn from ACCESS, a prospective cohort of HIV-positive PWUD in Vancouver, Canada. Generalized linear mixed-effects were used to model the independent effect of MMT on VL suppression across strata of frequency of cocaine injection and crack smoking (≥daily versus <daily), after adjustment for confounders.
  
  
  
  The analysis included 397 HIV-positive opioid users who completed ≥1 study interview between 2005 and 2014. At baseline, 304 (77%) reported participation in MMT, 37 (9%) ≥daily cocaine injection, and 158 (40%) ≥daily crack smoking. In adjusted analyses, MMT remained independently associated with increased odds of VL suppression in both strata of crack smokers (AOR=3.11, 95% CI: 1.86-5.21 and AOR=1.48, 95%CI: 1.04-2.09, for ≥daily and <daily smokers, respectively), and among <daily cocaine injectors (AOR=1.88, 95%CI 1.38-2.56), but not among ≥daily cocaine injectors (AOR=1.37, 95%CI 0.53-3.49). Longer retention on MMT was positively associated with VL suppression in all strata of cocaine injection and crack smoke.
  
  
  
  Exposure to MMT was associated with increased odds of VL suppression among HIV- positive opioid users regardless of crack use. However, this beneficial effect of MMT was lost among frequent cocaine injectors with shorter retention on MMT.
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors.forename: M Eugenia
authors.initials: ME
authors.lastname: Socías
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors.forename: Evan
authors.initials: E
authors.lastname: Wood
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; Faculty of Health Sciences, Simon Fraser University, Blusson Hall, Room 11300, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
authors.forename: Will
authors.initials: W
authors.lastname: Small
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors.forename: Huiru
authors.initials: H
authors.lastname: Dong
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver, BC, V6T 1Z3, Canada.
authors.forename: Jean
authors.initials: J
authors.lastname: Shoveller
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kerr
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors.forename: Julio
authors.initials: J
authors.lastname: Montaner
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada; Department of Medicine, University of British Columbia, St. Paul's Hospital, 608-1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada. Electronic address: uhri-mjsm@cfenet.ubc.ca.
authors.forename: M-J
authors.initials: MJ
authors.lastname: Milloy
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D002170:Canada; D003042:Cocaine; D019970:Cocaine-Related Disorders / Q000150:complications*; D016578:Crack Cocaine; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000821:virology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008691:Methadone / Q000627:therapeutic use*; D008875:Middle Aged; D058850:Opiate Substitution Treatment; D009293:Opioid-Related Disorders / Q000150:complications / Q000188:drug therapy*; D011446:Prospective Studies; D016896:Treatment Outcome; D019562:Viral Load
chemical_list: D000701:Analgesics, Opioid; D016578:Crack Cocaine; D003042:Cocaine; D008691:Methadone
keywords: Antiretroviral therapy; Cocaine; Methadone maintenance therapy; Opioid substitution treatment; Opioid use disorder; Viral suppression