title: A prospective study of predictors of adherence to combination antiretroviral medication.
abstract: OBJECTIVE
  Adherence to complex antiretroviral therapy (ART) is critical for HIV treatment but difficult to achieve. The development of interventions to improve adherence requires detailed information regarding barriers to adherence. However, short follow-up and inadequate adherence measures have hampered such determinations. We sought to assess predictors of long-term (up to 1 year) adherence to newly initiated combination ART using an accurate, objective adherence measure.
  
  
  METHODS
  A prospective cohort study of 140 HIV-infected patients at a county hospital HIV clinic during the year following initiation of a new highly active ART regimen.
  
  
  RESULTS
  We measured adherence every 4 weeks, computing a composite score from electronic medication bottle caps, pill count and self-report. We evaluated patient demographic, biomedical, and psychosocial characteristics, features of the regimen, and relationship with one's HIV provider as predictors of adherence over 48 weeks. On average, subjects took 71% of prescribed doses with over 95% of patients achieving suboptimal (<95%) adherence. In multivariate analyses, African-American ethnicity, lower income and education, alcohol use, higher dose frequency, and fewer adherence aids (e.g., pillboxes, timers) were independently associated with worse adherence. After adjusting for demographic and clinical factors, those actively using drugs took 59% of doses versus 72% for nonusers, and those drinking alcohol took 66% of doses versus 74% for nondrinkers. Patients with more antiretroviral doses per day adhered less well. Participants using no adherence aids took 68% of doses versus 76% for those in the upper quartile of number of adherence aids used.
  
  
  CONCLUSIONS
  Nearly all patients' adherence levels were suboptimal, demonstrating the critical need for programs to assist patients with medication taking. Interventions that assess and treat substance abuse and incorporate adherence aids may be particularly helpful and warrant further study.
authors.affiliation: Department of Health Behavior and Health Education, University of North Carolina at Chapel Hill, Sheps Center for Health Services Research, Chapel Hill, NC 27599-7590, USA. Carol_Golin@unc.edu
authors.forename: Carol E
authors.initials: CE
authors.lastname: Golin
authors.forename: Honghu
authors.initials: H
authors.lastname: Liu
authors.forename: Ron D
authors.initials: RD
authors.lastname: Hays
authors.forename: Loren G
authors.initials: LG
authors.lastname: Miller
authors.forename: C Keith
authors.initials: CK
authors.lastname: Beck
authors.forename: Jeanette
authors.initials: J
authors.lastname: Ickovics
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Kaplan
authors.forename: Neil S
authors.initials: NS
authors.lastname: Wenger
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000523:psychology; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D010349:Patient Compliance; D010358:Patient Participation; D011446:Prospective Studies
chemical_list: D019380:Anti-HIV Agents