title: The effect of injecting drug use history on disease progression and death among HIV-positive individuals initiating combination antiretroviral therapy: collaborative cohort analysis.
abstract: BACKGROUND
  We examined whether determinants of disease progression and causes of death differ between injecting drug users (IDUs) and non-IDUs who initiate combination antiretroviral therapy (cART).
  
  
  METHODS
  The ART Cohort Collaboration combines data from participating cohort studies on cART-naïve adults from cART initiation. We used Cox models to estimate hazard ratios for death and AIDS among IDUs and non-IDUs. The cumulative incidence of specific causes of death was calculated and compared using methods that allow for competing risks.
  
  
  RESULTS
  Data on 6269 IDUs and 37 774 non-IDUs were analysed. Compared with non-IDUs, a lower proportion of IDUs initiated cART with a CD4 cell count <200 cells/μL or had a prior diagnosis of AIDS. Mortality rates were higher in IDUs than in non-IDUs (2.08 vs. 1.04 per 100 person-years, respectively; P<0.001). Lower baseline CD4 cell count, higher baseline HIV viral load, clinical AIDS at baseline, and later year of cART initiation were associated with disease progression in both groups. However, the inverse association of baseline CD4 cell count with AIDS and death appeared stronger in non-IDUs than in IDUs. The risk of death from each specific cause was higher in IDUs than non-IDUs, with particularly marked increases in risk for liver-related deaths, and those from violence and non-AIDS infection.
  
  
  CONCLUSIONS
  While liver-related deaths and deaths from direct effects of substance abuse appear to explain much of the excess mortality in IDUs, they are at increased risk for many other causes of death, which may relate to suboptimal management of HIV disease in these individuals.
authors.affiliation: Division of Infectious Diseases, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Murray
authors.forename: R S
authors.initials: RS
authors.lastname: Hogg
authors.forename: V D
authors.initials: VD
authors.lastname: Lima
authors.forename: M T
authors.initials: MT
authors.lastname: May
authors.forename: D M
authors.initials: DM
authors.lastname: Moore
authors.forename: S
authors.initials: S
authors.lastname: Abgrall
authors.forename: M
authors.initials: M
authors.lastname: Bruyand
authors.forename: A
authors.initials: A
authors.lastname: D'Arminio Monforte
authors.forename: C
authors.initials: C
authors.lastname: Tural
authors.forename: M J
authors.initials: MJ
authors.lastname: Gill
authors.forename: R J
authors.initials: RJ
authors.lastname: Harris
authors.forename: P
authors.initials: P
authors.lastname: Reiss
authors.forename: A
authors.initials: A
authors.lastname: Justice
authors.forename: O
authors.initials: O
authors.lastname: Kirk
authors.forename: M
authors.initials: M
authors.lastname: Saag
authors.forename: C J
authors.initials: CJ
authors.lastname: Smith
authors.forename: R
authors.initials: R
authors.lastname: Weber
authors.forename: J
authors.initials: J
authors.lastname: Rockstroh
authors.forename: P
authors.initials: P
authors.lastname: Khaykin
authors.forename: J A C
authors.initials: JA
authors.lastname: Sterne
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000401:mortality; D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D018450:Disease Progression; D004359:Drug Therapy, Combination; D055030:Drug Users / Q000706:statistics & numerical data*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000209:etiology / Q000276:immunology / Q000401:mortality*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D016016:Proportional Hazards Models; D012367:RNA, Viral / Q000097:blood; D012307:Risk Factors; D015819:Substance Abuse, Intravenous / Q000150:complications* / Q000401:mortality*; D019562:Viral Load; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents; D012367:RNA, Viral