title: Hormonal contraception does not increase women's HIV acquisition risk in Zambian discordant couples, 1994-2012.
abstract: OBJECTIVE
  To determine the impact of hormonal contraceptive methods on risk of HIV acquisition among HIV-negative women cohabiting with HIV-positive male partners.
  
  
  METHODS
  From 1994-2012, HIV discordant couples recruited from a couples' voluntary HIV counseling and testing center in Lusaka, Zambia were followed longitudinally. HIV-negative partners were tested quarterly. This analysis is restricted to couples in which the man was HIV-positive and the woman was HIV-negative at enrollment and the man was not on antiretroviral treatment. Multivariate Cox models evaluated associations between time-varying contraceptive methods and HIV acquisition among women. Sensitivity analyses explored exposure misclassification and time-varying confounder mediation.
  
  
  RESULTS
  Among 1393 couples, 252 incident infections occurred in women over 2842 couple-years (8.9 infections per 100 couple-years; 95% CI, 7.8-10.0). Multivariate Cox models indicated that neither injectable [adjusted hazard ratio (aHR)=1.2; 95% CI, 0.8-1.7], oral contraceptive pill (OCP, aHR=1.3; 95% CI, 0.9-1.8), or implant (aHR=1.1; 95% CI, 0.5-2.2) use was significantly associated with HIV acquisition relative to non-hormonal contraception controlling for woman's age, literacy and time-varying measures of genital ulceration/inflammation. This remained true when only looking at the subset of infections acquired from the spouse (82% of infections) and additionally controlling for baseline HIV viral load of the male partner, pregnancy status, and time-varying measures of sperm on a vaginal swab wet prep and self-reported unprotected sex. OCP and injectable users reported more unprotected sex (p<.001), and OCP users were more likely to have sperm on vaginal swab (p=.1) than nonhormonal method users.
  
  
  CONCLUSIONS
  We found no association between hormonal contraception and HIV acquisition risk in women. Condom use and reinforced condom counseling should always be recommended for HIV discordant couples. HIV testing of sex partners together is critical to establish HIV risk, ascertain couple fertility intentions and counsel appropriately.
  
  
  CONCLUSIONS
  These findings add to a controversial literature and uniquely address several common design and analytic challenges faced by previous studies. After controlling for confounders, we found no association between hormonal contraception and HIV acquisition risk in women. We support promoting condoms for HIV prevention and increasing the contraceptive method mix to decrease unintended pregnancy.
authors.affiliation: Rwanda Zambia HIV Research Group, Department of Pathology & Laboratory Medicine, School of Medicine and Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA; Department of Epidemiology, Rollins School of Public Health, Laney Graduate School, Emory University, Atlanta, GA, USA. Electronic address: kmwall@emory.edu.
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Wall
authors.affiliation: Rwanda Zambia HIV Research Group, Department of Pathology & Laboratory Medicine, School of Medicine and Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
authors.forename: William
authors.initials: W
authors.lastname: Kilembe
authors.affiliation: Rwanda Zambia HIV Research Group, Department of Pathology & Laboratory Medicine, School of Medicine and Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA; Department of Gynecology and Obstetrics, School of Medicine, University of Zambia, Lusaka, Zambia.
authors.forename: Bellington
authors.initials: B
authors.lastname: Vwalika
authors.affiliation: Rwanda Zambia HIV Research Group, Department of Pathology & Laboratory Medicine, School of Medicine and Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
authors.forename: Naw
authors.initials: N
authors.lastname: Htee Khu
authors.affiliation: Department of Epidemiology, Ryals School of Public Health, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Ilene
authors.initials: I
authors.lastname: Brill
authors.affiliation: Rwanda Zambia HIV Research Group, Department of Pathology & Laboratory Medicine, School of Medicine and Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA; Ministry of Community Development, Mother and Child Health, Lusaka, Zambia.
authors.forename: Elwyn
authors.initials: E
authors.lastname: Chomba
authors.affiliation: Department of Biostatistics and Computational Biology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, USA.
authors.forename: Brent A
authors.initials: BA
authors.lastname: Johnson
authors.affiliation: Rwanda Zambia HIV Research Group, Department of Pathology & Laboratory Medicine, School of Medicine and Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA; Department of Gynecology and Obstetrics, Emory University, School of Medicine, Atlanta, GA, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Haddad
authors.affiliation: Rwanda Zambia HIV Research Group, Department of Pathology & Laboratory Medicine, School of Medicine and Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Tichacek
authors.affiliation: Rwanda Zambia HIV Research Group, Department of Pathology & Laboratory Medicine, School of Medicine and Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Allen
mesh_terms: D000328:Adult; D003267:Contraception / Q000379:methods*; D003268:Contraception Behavior / Q000706:statistics & numerical data*; D003278:Contraceptives, Oral, Hormonal / Q000627:therapeutic use*; D005191:Family Characteristics; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000517:prevention & control / Q000635:transmission*; D006679:HIV Seropositivity; D059147:HIV Serosorting; D015497:HIV-1 / Q000276:immunology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011247:Pregnancy; D049168:Pregnancy, Unplanned; D016016:Proportional Hazards Models; D012307:Risk Factors; D012747:Sexual Partners; D047568:Unsafe Sex; D019562:Viral Load; D015024:Zambia
chemical_list: D003278:Contraceptives, Oral, Hormonal
keywords: Discordant couples; HIV risk; Hormonal contraception; Longitudinal cohort; Women; Zambia