title: Factors associated with optimal pharmacy refill adherence for antiretroviral medications and plasma HIV RNA non-detectability among HIV-positive crack cocaine users: a prospective cohort study.
abstract: Crack cocaine use is known to contribute to poor adherence to antiretroviral medications; however, little is known about facilitators of or barriers to effective HIV treatment use among HIV-infected crack cocaine users. We sought to identify correlates of optimal pharmacy refill adherence for antiretroviral medications and plasma HIV RNA viral load (pVL) suppression among this population.
  
  
  
  Data from a prospective cohort of HIV-positive people who use illicit drugs in Vancouver, Canada, were linked to comprehensive HIV clinical monitoring and pharmacy dispensation records. We used multivariable generalized linear mixed-effects modelling to longitudinally identify factors associated with ≥95 % adherence to pharmacy refills for antiretroviral medications and pVL <50 copies/mL among crack cocaine users exposed to highly-active antiretroviral therapy (HAART).
  
  
  
  Among 438 HAART-exposed crack cocaine users between 2005 and 2013, 240 (54.8 %) had ≥95 % pharmacy refill adherence in the previous 6 months at baseline. In multivariable analyses, homelessness (adjusted odds ratio [AOR]: 0.58), ≥daily crack cocaine smoking (AOR: 0.64), and ≥ daily heroin use (AOR: 0.43) were independently associated with optimal pharmacy refill adherence (all p < 0.05). The results for pVL non-detectability were consistent with those of medication adherence, except that longer history of HAART (AOR: 1.06), receiving a single tablet-per-day regimen (AOR: 3.02) and participation in opioid substitution therapies was independently associated with pVL non-detectability (AOR: 1.55) (all p < 0.05).
  
  
  
  Homelessness, and daily crack cocaine and/or heroin use were independently and negatively associated with optimal HAART-related outcomes. With the exception of opioid substitution therapies, no addiction treatment modalities assessed appeared to facilitate medication adherence or viral suppression. Evidence-based treatment options for crack cocaine use that also confer benefits to HAART need to be developed.
authors: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.|Division of AIDS, Department of Medicine, University of British Columbia, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors: Kanna
authors: K
authors: Hayashi
authors: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.|Division of AIDS, Department of Medicine, University of British Columbia, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors: Evan
authors: E
authors: Wood
authors: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.|Division of AIDS, Department of Medicine, University of British Columbia, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors: Thomas
authors: T
authors: Kerr
authors: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors: Huiru
authors: H
authors: Dong
authors: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors: Paul
authors: P
authors: Nguyen
authors: 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, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
authors: Cathy M
authors: CM
authors: Puskas
authors: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors: Silvia
authors: S
authors: Guillemi
authors: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.|Division of AIDS, Department of Medicine, University of British Columbia, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada.
authors: Julio S G
authors: JS
authors: Montaner
authors: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada. uhri-mjsm@cfenet.ubc.ca.|Division of AIDS, Department of Medicine, University of British Columbia, 608 - 1081 Burrard Street, Vancouver, BC, V6Z 1Y6, Canada. uhri-mjsm@cfenet.ubc.ca.
authors: Michael-John
authors: MJ
authors: Milloy
mesh_terms: D000328:Adult; D023241:Antiretroviral Therapy, Highly Active / Q000706:statistics & numerical data*; D002170:Canada; D016578:Crack Cocaine; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000235:genetics; D006801:Humans; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D011446:Prospective Studies; D012367:RNA, Viral / Q000097:blood*; D016896:Treatment Outcome
chemical_list: D016578:Crack Cocaine; D012367:RNA, Viral
keywords: ART adherence; Addiction treatment; Crack cocaine; Plasma HIV-1 RNA viral load suppression