title: Preventing unintended pregnancy and HIV transmission: effects of the HIV treatment cascade on contraceptive use and choice in rural KwaZulu-Natal.
abstract: BACKGROUND
  For women living with HIV, contraception using condoms is recommended because it prevents not only unintended pregnancy but also acquisition of other sexually transmitted infections and onward transmission of HIV. Dual-method dual-protection contraception (condoms with other contraceptive methods) is preferable over single-method dual-protection contraception (condoms alone) because of its higher contraceptive effectiveness. We estimate the effect of progression through the HIV treatment cascade on contraceptive use and choice among HIV-infected women in rural South Africa.
  
  
  METHODS
  We linked population-based surveillance data on contraception collected by the Wellcome Trust Africa Centre for Health and Population Studies to data from the local antiretroviral treatment (ART) program in Hlabisa subdistrict, KwaZulu-Natal. In bivariate probit regression, we estimated the effects of progressing through the cascade on contraceptive choice among HIV-infected sexually active women aged 15-49 years (N = 3169), controlling for a wide range of potential confounders.
  
  
  RESULTS
  Contraception use increased across the cascade from <40% among HIV-infected women who did not know their status to >70% among women who have been on ART for 4-7 years. Holding other factors equal (1) awareness of HIV status, (2) ART initiation, and (3) being on ART for 4-7 years increased the likelihood of single-method/dual-method dual protection by the following percentage points (pp), compared with women who were unaware of their HIV status: (1) 4.6 pp (P = 0.030)/3.5 pp (P = 0.001), (2) 10.3 pp (P = 0.003)/5.2 pp (P = 0.007), and (3) 21.6 pp (P < 0.001)/11.2 pp (P < 0.001).
  
  
  CONCLUSIONS
  Progression through the HIV treatment cascade significantly increased the likelihood of contraception in general and contraception with condoms in particular. ART programs are likely to contribute to HIV prevention through the behavioral pathway of changing contraception use and choice.
authors.affiliation: *Department of Global Health and Population, Harvard School of Public Health, Boston, MA; †Wellcome Trust Africa Centre for Health and Population Studies, Mtubatuba, South Africa; and ‡Division of Infection & Immunity University College London, London, United Kingdom.
authors.forename: Julia
authors.initials: J
authors.lastname: Raifman
authors.forename: Terusha
authors.initials: T
authors.lastname: Chetty
authors.forename: Frank
authors.initials: F
authors.lastname: Tanser
authors.forename: Tinofa
authors.initials: T
authors.lastname: Mutevedzi
authors.forename: Philippa
authors.initials: P
authors.lastname: Matthews
authors.forename: Kobus
authors.initials: K
authors.lastname: Herbst
authors.forename: Deenan
authors.initials: D
authors.lastname: Pillay
authors.forename: Till
authors.initials: T
authors.lastname: Bärnighausen
mesh_terms: D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D003267:Contraception / Q000523:psychology / Q000706:statistics & numerical data; D003268:Contraception Behavior / Q000706:statistics & numerical data; D003270:Contraceptive Agents / Q000627:therapeutic use*; D003273:Contraceptive Devices / Q000706:statistics & numerical data*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000635:transmission*; D006801:Humans; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D008875:Middle Aged; D011247:Pregnancy; D049168:Pregnancy, Unplanned / Q000523:psychology*; D013019:South Africa; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents; D003270:Contraceptive Agents