title: Comparison of subjective and objective adherence measures for preexposure prophylaxis against HIV infection among serodiscordant couples in East Africa.
abstract: BACKGROUND
  Preexposure prophylaxis (PrEP) efficacy is highly dependent on adherence. Yet, it is unclear which adherence measures perform best for PrEP.
  
  
  METHODS
  We compared three types of self-reported adherence questions (rating of ability to adhere, frequency of doses taken, percentage of doses taken) and three forms of objective adherence measurement [unannounced pill counts (UPC), electronic monitoring, plasma tenofovir levels] using data from an ancillary adherence study within a clinical trial of PrEP among East African serodiscordant couples (Partners PrEP Study). Monthly measures were assessed for the first 6 months of follow-up.
  
  
  RESULTS
  One thousand, one hundred and forty-seven participants contributed 6048 person-months of data to this analysis. Median adherence was high: self-reported rating (90%), self-reported frequency (93%), and self-reported percentage (97%); UPC (99%); and electronic monitoring (97%). Prevalence of steady-state daily dosing (SSDD; ≥40 ng/ml) was 74% in a random subset of tenofovir samples obtained from 365 participants. Discrimination of SSDD versus less than SSDD levels was poor for self-reported rating [area under the receiver-operating curve (AROC) 0.54], self-reported frequency (AROC 0.52), self-reported percentage (AROC 0.56) and UPC (AROC 0.58), but moderate for electronic monitoring (AROC 0.70). Correlation was moderate among self-reported measures, adherence (0.61-0.66), but low for these self-reported measures compared with UPC (0.32-0.36) and with electronic monitoring (0.22-0.28).
  
  
  CONCLUSIONS
  Electronic monitoring was the only adherence measure with meaningful ability to discriminate between SSDD and less than SSDD plasma tenofovir levels. Correlation between subjective and objective measures was poor. Future research should explore novel approaches to adherence measurement as PrEP moves into demonstration projects and programmatic implementation.
authors.affiliation: aDepartment of Medicine, Mbarara University of Science and Technology bEpiCentre/Médecins Sans Frontières cDepartment of Medical Laboratory Sciences, Mbarara University of Science and Technology, Mbarara, Uganda dDepartment of Infectious Diseases, University of Manitoba, Winnipeg, Canada eDepartment of Medicine, Division of Clinical Pharmacology, Johns Hopkins University, Baltimore, Maryland fDepartment of Global Health gDepartment of Medicine hDepartment of Epidemiology, University of Washington, Seattle, Washington iDepartment of Medicine, Harvard Medical School jDepartment of Global Health and Populations, Harvard T.H. Chan School of Public Health Center for Global Health, Massachusetts General Hospital, Boston, Massachusetts, USA. *Members of the "The Partners PrEP Ancillary Adherence Study Team" have been mentioned under Acknowledgements section.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Musinguzi
authors.forename: Collins D
authors.initials: CD
authors.lastname: Muganzi
authors.forename: Yap
authors.initials: Y
authors.lastname: Boum
authors.forename: Allan
authors.initials: A
authors.lastname: Ronald
authors.forename: Mark A
authors.initials: MA
authors.lastname: Marzinke
authors.forename: Craig W
authors.initials: CW
authors.lastname: Hendrix
authors.forename: Connie
authors.initials: C
authors.lastname: Celum
authors.forename: Jared M
authors.initials: JM
authors.lastname: Baeten
authors.forename: David R
authors.initials: DR
authors.lastname: Bangsberg
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Haberer
mesh_terms: D000328:Adult; D000351:Africa, Eastern; D044966:Anti-Retroviral Agents / Q000008:administration & dosage*; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D004311:Double-Blind Method; D005191:Family Characteristics; D005260:Female; D015658:HIV Infections / Q000517:prevention & control*; D006801:Humans; D008297:Male; D055118:Medication Adherence; D065129:Pre-Exposure Prophylaxis / Q000379:methods* / Q000706:statistics & numerical data*; D000068698:Tenofovir / Q000008:administration & dosage
chemical_list: D044966:Anti-Retroviral Agents; D000068698:Tenofovir