title: Low versus high CD4 cell count as starting point for introduction of antiretroviral treatment in resource-poor settings: a scenario-based analysis.
abstract: OBJECTIVE
  To evaluate CD4 cell count-driven strategies for the initiation of highly active antiretroviral therapy (HAART) in terms of the reduction of the incidence of AIDS-defining events in resource-poor settings.
  
  
  METHODS
  Data from the Amsterdam Cohort Study on HIV infection and AIDS were used to estimate the hazard of AIDS in untreated HIV-1 infection and after initiation of HAART, respectively, conditional on CD4 cell count. Different strategies for initiating therapy were compared by calculating the expected HAART administration rate and 1-year cumulative AIDS incidence in three different population settings, varying in the stage of HIV-1 infection at the time of presentation.
  
  
  RESULTS
  Among 695 HIV-1-infected cohort participants, the 1-year AIDS incidence density (ID) ranged from 3.2 per 100 person-years for CD4 cell counts 600-700 cells/mm3, to 31.9 per 100 person-years for CD4 cell counts 100-200 cells/mm3 and 77.9 per 100 person-years for CD4 cell counts below 100 cells/mm3. Upon initiation of HAART, the ID in the lowest CD4 strata declined to 13.3 and 16.3 per 100 person-years, respectively. Extrapolated to developing countries, supply of HAART to patients presenting with HIV-1 infection below 200 CD4 cells/mm3 is expected to give an administration rate of 67%, while the AIDS incidence will drop from over 30% to almost 10%.
  
  
  CONCLUSIONS
  Introduction of HAART in populations with advanced HIV-1 infection can accomplish a threefold reduction of the AIDS incidence when HAART is administered to patients with CD4 cell counts below 200 cells/mm3. In a hospital-based setting in resource-poor environments this ensures an efficient treatment allocation.
authors.affiliation: Department of Human Retrovirology, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Bogaards
authors.forename: Gerrit Jan
authors.initials: GJ
authors.lastname: Weverling
authors.forename: Ronald B
authors.initials: RB
authors.lastname: Geskus
authors.forename: Frank
authors.initials: F
authors.lastname: Miedema
authors.forename: Joep M A
authors.initials: JM
authors.lastname: Lange
authors.forename: Patrick M M
authors.initials: PM
authors.lastname: Bossuyt
authors.forename: Jaap
authors.initials: J
authors.lastname: Goudsmit
mesh_terms: D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D003906:Developing Countries; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000503:physiopathology*; D018451:Homosexuality, Male; D006801:Humans; D007165:Immunosuppression Therapy; D015994:Incidence; D008297:Male; D008507:Medically Underserved Area; D008954:Models, Biological; D013997:Time Factors