title: Correlation between pill counts and biologic effects in an HIV-1 prevention clinical trial: implications for measuring adherence.
abstract: Clinic-based pill counts of unused study medication are frequently used to measure adherence in HIV-1 prevention trials. Monthly pill count adherence data from the Partners in Prevention HSV/HIV Transmission Study, a double-blind, placebo controlled trial of twice-daily acyclovir suppression of herpes simplex virus type 2 (HSV-2) in HIV-1 infected persons was used to compare changes between 3,381 placebo and active arm participants in two objective biologic measures of acyclovir's drug activity: reduction in plasma HIV-1 RNA and HSV-2 genital ulcer disease (GUD). Higher acyclovir pill count adherence was associated with greater reductions in plasma HIV-1 RNA and GUD, indicating pill count data is strongly correlated with biological effects of adherence. However, when calculated adherence exceeded 102 % (i.e., fewer pills returned than expected) and when pill counts were missing because bottles were not returned, plasma HIV-1 RNA and GUD effects were diminished, likely indicating periods of non-adherence.
authors.affiliation: Department of Global Health, University of Washington, Seattle, USA. deborah@scharp.org
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Donnell
authors.forename: Jared M
authors.initials: JM
authors.lastname: Baeten
authors.forename: Ting
authors.initials: T
authors.lastname: Hong
authors.forename: Jairam R
authors.initials: JR
authors.lastname: Lingappa
authors.forename: Andrew
authors.initials: A
authors.lastname: Mujugira
authors.forename: Edith
authors.initials: E
authors.lastname: Nakku-Joloba
authors.forename: David
authors.initials: D
authors.lastname: Bangsberg
authors.forename: Connie
authors.initials: C
authors.lastname: Celum
mesh_terms: D000212:Acyclovir / Q000008:administration & dosage*; D000328:Adult; D000349:Africa / Q000453:epidemiology; D000998:Antiviral Agents / Q000008:administration & dosage*; D018791:CD4 Lymphocyte Count; D004311:Double-Blind Method; D016903:Drug Monitoring / Q000295:instrumentation; D005191:Family Characteristics; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control*; D015497:HIV-1 / Q000187:drug effects*; D006558:Herpes Genitalis / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D012367:RNA, Viral; D015203:Reproducibility of Results; D019562:Viral Load
chemical_list: D000998:Antiviral Agents; D012367:RNA, Viral; D000212:Acyclovir