title: Adherence to extended postpartum antiretrovirals is associated with decreased breast milk HIV-1 transmission.
abstract: OBJECTIVE
  Estimate association between postpartum antiretroviral adherence and breast milk HIV-1 transmission.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Mother-infant pairs were randomized after delivery to immediately begin receiving 28 weeks of either triple maternal antiretrovirals (zidovudine, lamivudine, and either nevirapine, nelfinavir, or lopinavir-ritonavir) or daily infant nevirapine as part of the Breastfeeding, Antiretrovirals, and Nutrition (BAN) study. Associations between postpartum antiretroviral adherence and rate of breast milk HIV-1 transmission were estimated using Cox models. We measured adherence over four postpartum time intervals using pill count, suspension bottle weight, and maternal self-report. Adherence was categorized and lagged by one interval. Missing adherence measures were multiply imputed. Infant HIV-1 infection was determined by DNA PCR every 2-6 weeks. The primary endpoint was infant HIV-1 infection by 38 weeks of age among infants alive and uninfected at 5 weeks.
  
  
  RESULTS
  Analyses included 1479 mother-infant pairs and 45 transmission events. Using pill count and bottle weight information, 22-40% of mother-infant pairs at any given interval were less than 90% adherent. Having at least 90% adherence was associated with a 52% [95% confidence interval (CI) 3-76] relative reduction in the rate of breast milk HIV-1 transmission, compared with having less than 90% adherence when controlling for study arm, breastfeeding status, and maternal characteristics. Complete case analysis rendered similar results (n = 501; relative reduction 59%, 95% CI 6-82).
  
  
  CONCLUSIONS
  Nonadherence to extended postpartum antiretroviral regimens in 'real world' settings is likely to be higher than that seen in BAN. Identifying mothers with difficulty adhering to antiretrovirals, and developing effective adherence interventions, will help maximize benefits of antiretroviral provision throughout breastfeeding.
authors.affiliation: aDepartment of Epidemiology, Gillings School of Global Public Health, University of North Carolina bDivision of Infectious Diseases, Department of Medicine, School of Medicine, University of North Carolina cDepartment of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA dDivision of Epidemiology and Biostatistics, School of Public Health, University of Witwatersrand, Parktown, South Africa eUniversity of North Carolina, UNC Project, Lilongwe, Malawi fDepartment of Microbiology and Immunology, School of Medicine; Center for AIDS Research, University of North Carolina gGlobal Women's Health Division, Department of Obstetrics & Gynecology; Institute for Global Health and Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, North Carolina hDivision of Reproductive Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Nicole L
authors.initials: NL
authors.lastname: Davis
authors.forename: William C
authors.initials: WC
authors.lastname: Miller
authors.forename: Michael G
authors.initials: MG
authors.lastname: Hudgens
authors.forename: Charles S
authors.initials: CS
authors.lastname: Chasela
authors.forename: Dorothy
authors.initials: D
authors.lastname: Sichali
authors.forename: Dumbani
authors.initials: D
authors.lastname: Kayira
authors.forename: Julie A E
authors.initials: JA
authors.lastname: Nelson
authors.forename: Jeffrey S A
authors.initials: JS
authors.lastname: Stringer
authors.forename: Sascha R
authors.initials: SR
authors.lastname: Ellington
authors.forename: Athena P
authors.initials: AP
authors.lastname: Kourtis
authors.forename: Denise J
authors.initials: DJ
authors.lastname: Jamieson
authors.forename: Charles
authors.initials: C
authors.lastname: van der Horst
mesh_terms: D000293:Adolescent; D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D001942:Breast Feeding; D015331:Cohort Studies; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000517:prevention & control / Q000635:transmission*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D008895:Milk, Human / Q000821:virology; D049590:Postpartum Period; D011247:Pregnancy; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D044966:Anti-Retroviral Agents