title: Predictors of viral suppression and rebound among HIV-positive men who have sex with men in a large multi-site Canadian cohort.
abstract: BACKGROUND
  Gay, bisexual and other men who have sex with men (MSM) are disproportionately affected by HIV in Canada. Combination antiretroviral therapy has been shown to dramatically decrease progression to AIDS, premature death and HIV transmission. However, there are no comprehensive data regarding combination antiretroviral therapy outcomes among this population. We sought to identify socio-demographic and clinical correlates of viral suppression and rebound.
  
  
  METHODS
  Our analysis included MSM participants in the Canadian Observational Cohort, a multi-site cohort of HIV-positive adults from Canada's three most populous provinces, aged ≥18 years who first initiated combination antiretroviral therapy between 2000 and 2011. We used accelerated failure time models to identify factors predicting time to suppression (2 measures <50 copies/mL ≥30 days apart) and subsequent rebound (2 measures >200 copies/mL ≥30 days apart).
  
  
  RESULTS
  Of 2,858 participants, 2,448 (86 %) achieved viral suppression in a median time of 5 months (Q1-Q3: 3-7 months). Viral suppression was significantly associated with later calendar year of antiretroviral therapy initiation, no history of injection drug use, lower baseline viral load, being on an initial regimen consisting of non-nucleoside reverse-transcriptase inhibitors, and older age. Among those who suppressed, 295 (12 %) experienced viral rebound. This was associated with earlier calendar year of antiretroviral therapy initiation, injection drug use history, younger age, higher baseline CD4 cell count, and living in British Columbia.
  
  
  CONCLUSIONS
  Further strategies are required to optimize combination antiretroviral therapy outcomes in men who have sex with men in Canada, specifically targeting younger MSM and those with a history of injection drug use.
authors: BC Centre for Excellence in HIV/AIDS, Vancouver, Canada.
authors: Zachary
authors: Z
authors: Tanner
authors: BC Centre for Excellence in HIV/AIDS, Vancouver, Canada.|School of Public Health & Social Policy, University of Victoria, Victoria, Canada.|Centre for Addiction Research British Columbia, University of Victoria, Victoria, Canada.
authors: Nathan
authors: N
authors: Lachowsky
authors: BC Centre for Excellence in HIV/AIDS, Vancouver, Canada.
authors: Erin
authors: E
authors: Ding
authors: BC Centre for Excellence in HIV/AIDS, Vancouver, Canada.
authors: Hasina
authors: H
authors: Samji
authors: BC Centre for Excellence in HIV/AIDS, Vancouver, Canada.|Faculty of Medicine, University of British Columbia, Vancouver, Canada.
authors: Mark
authors: M
authors: Hull
authors: Northern Ontario School of Medicine, Sudbury, Canada.
authors: Angela
authors: A
authors: Cescon
authors: BC Centre for Excellence in HIV/AIDS, Vancouver, Canada.|Faculty of Health Sciences, Simon Fraser University, Vancouver, Canada.
authors: Sophie
authors: S
authors: Patterson
authors: BC Centre for Excellence in HIV/AIDS, Vancouver, Canada.
authors: Jason
authors: J
authors: Chia
authors: BC Centre for Excellence in HIV/AIDS, Vancouver, Canada.
authors: Alia
authors: A
authors: Leslie
authors: Dalla Lana School of Public Health, University of Toronto, Toronto, Canada.|Toronto General Research Institute, University Health Network, Toronto, Canada.
authors: Janet
authors: J
authors: Raboud
authors: Dalla Lana School of Public Health, University of Toronto, Toronto, Canada.|Faculty of Medicine, University of Toronto, Toronto, Canada.|Maple Leaf Medical Clinic, Toronto, Canada.|Women's College Research Institute, Women's College Hospital, Toronto, Canada.
authors: Mona
authors: M
authors: Loutfy
authors: The Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Canada.
authors: Curtis
authors: C
authors: Cooper
authors: Faculty of Medicine, McGill University, Montreal, Canada.|The Montreal Chest Institute, McGill University Health Centre, Montreal, Canada.
authors: Marina
authors: M
authors: Klein
authors: Clinique Medicale l'Actuel, Montreal, Canada.
authors: Nima
authors: N
authors: Machouf
authors: Faculty of Medicine, McGill University, Montreal, Canada.
authors: Christos
authors: C
authors: Tsoukas
authors: BC Centre for Excellence in HIV/AIDS, Vancouver, Canada.|Faculty of Medicine, University of British Columbia, Vancouver, Canada.
authors: Julio
authors: J
authors: Montaner
authors: BC Centre for Excellence in HIV/AIDS, Vancouver, Canada. robert_hogg@sfu.ca.|Faculty of Health Sciences, Simon Fraser University, Vancouver, Canada. robert_hogg@sfu.ca.|Faculty of Health Sciences, Simon Fraser University, BLU 9512, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada. robert_hogg@sfu.ca.
authors: Robert S
authors: RS
authors: Hogg
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D001955:British Columbia; D018791:CD4 Lymphocyte Count; D002170:Canada; D015331:Cohort Studies; D018450:Disease Progression; D015658:HIV Infections / Q000188:drug therapy*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D008875:Middle Aged; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use; D015819:Substance Abuse, Intravenous; D016896:Treatment Outcome; D019562:Viral Load / Q000187:drug effects
chemical_list: D019380:Anti-HIV Agents; D018894:Reverse Transcriptase Inhibitors
keywords: Canada; HIV; MSM; Rebound; Suppression; Viral load