title: Gender differences in clinical outcomes among HIV-positive individuals on antiretroviral therapy in Canada: a multisite cohort study.
abstract: BACKGROUND
  Cohort data examining differences by gender in clinical responses to combination antiretroviral therapy (ART) remain inconsistent and have yet to be explored in a multi-province Canadian setting. This study investigates gender differences by injection drug use (IDU) history in virologic responses to ART and mortality.
  
  
  METHODS
  Data from the Canadian Observational Cohort (CANOC) collaboration, a multisite cohort study of HIV-positive individuals initiating ART after January 1, 2000, were included. This analysis was restricted to participants with a follow-up HIV-RNA plasma viral load measure and known IDU history. Weibull hazard regression evaluated time to virologic suppression (2 consecutive measures <50 copies/mL), rebound (>1000 copies/mL after suppression), and all-cause mortality. Sensitivity analyses explored the impact of presumed ART use in pregnancy on virologic outcomes.
  
  
  RESULTS
  At baseline, women (1120 of 5442 participants) were younger (median 36 vs. 41 years) and more frequently reported IDU history (43.5% vs. 28.8%) (both p<0.001). Irrespective of IDU history, in adjusted multivariable analyses women were significantly less likely to virologically suppress after ART initiation and were at increased risk of viral load rebound. In adjusted time to death analysis, no differences by gender were noted. After adjusting for presumed ART use in pregnancy, observed gender differences in time to virologic suppression for non-IDU, and time to virologic rebound for IDU, became insignificant.
  
  
  CONCLUSIONS
  HIV-positive women in CANOC are at heightened risk for poor clinical outcomes. Further understanding of the intersections between gender and other factors augmenting risk is needed to maximize the benefits of ART.
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada.
authors.forename: Angela
authors.initials: A
authors.lastname: Cescon
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada ; Faculty of Health Sciences, Simon Fraser University, Burnaby, Canada.
authors.forename: Sophie
authors.initials: S
authors.lastname: Patterson
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada.
authors.forename: Keith
authors.initials: K
authors.lastname: Chan
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada ; Faculty of Health Sciences, Simon Fraser University, Burnaby, Canada.
authors.forename: Alexis K
authors.initials: AK
authors.lastname: Palmer
authors.affiliation: Canadian Observational Cohort (CANOC) collaboration, Toronto, Canada.
authors.forename: Shari
authors.initials: S
authors.lastname: Margolese
authors.affiliation: Ontario HIV Treatment Network, Toronto, Canada.
authors.forename: Ann N
authors.initials: AN
authors.lastname: Burchell
authors.affiliation: University of Ottawa, The Ottawa Hospital Research Institute, Ottawa, Canada.
authors.forename: Curtis
authors.initials: C
authors.lastname: Cooper
authors.affiliation: Department of Medicine, McGill University, Montreal, Canada ; Montreal Chest Institute, McGill University Health Centre, Montreal, Canada.
authors.forename: Marina B
authors.initials: MB
authors.lastname: Klein
authors.affiliation: Clinique médicale l'Actuel, Montreal, Canada.
authors.forename: Nima
authors.initials: N
authors.lastname: Machouf
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada ; Division of AIDS, Department of Medicine, University of British Columbia, Vancouver, Canada.
authors.forename: Julio S G
authors.initials: JS
authors.lastname: Montaner
authors.affiliation: Department of Medicine, McGill University, Montreal, Canada.
authors.forename: Chris
authors.initials: C
authors.lastname: Tsoukas
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, Vancouver, Canada ; Faculty of Health Sciences, Simon Fraser University, Burnaby, Canada.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Hogg
authors.affiliation: Dalla Lana School of Public Health, University of Toronto, Toronto, Canada ; Division of Infectious Diseases, University Health Network, Toronto, Canada.
authors.forename: Janet M
authors.initials: JM
authors.lastname: Raboud
authors.affiliation: Women's College Research Institute, Women's College Hospital, Toronto, Canada ; Maple Leaf Medical Clinic, Toronto, Canada ; Department of Medicine, University of Toronto, Toronto, Canada.
authors.forename: Mona R
authors.initials: MR
authors.lastname: Loutfy
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D002170:Canada; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy / Q000821:virology; D012307:Risk Factors; D012727:Sex Characteristics; D015819:Substance Abuse, Intravenous / Q000150:complications; D013997:Time Factors; D016896:Treatment Outcome; D019562:Viral Load
chemical_list: D019380:Anti-HIV Agents