title: Self-reported non-adherence to antiretroviral therapy repeatedly assessed by two questions predicts treatment failure in virologically suppressed patients.
abstract: BACKGROUND
  The aim of this study was to explore the predictive value of longitudinal self-reported adherence data on viral rebound.
  
  
  METHODS
  Individuals in the Swiss HIV Cohort Study on combined antiretroviral therapy (cART) with RNA <50 copies/ml over the previous 3 months and who were interviewed about adherence at least once prior to 1 March 2007 were eligible. Adherence was defined in terms of missed doses of cART (0, 1, 2 or >2) in the previous 28 days. Viral rebound was defined as RNA >500 copies/ml. Cox regression models with time-independent and -dependent covariates were used to evaluate time to viral rebound.
  
  
  RESULTS
  A total of 2,664 individuals and 15,530 visits were included. Across all visits, missing doses were reported as follows: 1 dose 14.7%, 2 doses 5.1%, >2 doses 3.8% taking <95% of doses 4.5% and missing > or =2 consecutive doses 3.2%. In total, 308 (11.6%) patients experienced viral rebound. After controlling for confounding variables, self-reported non-adherence remained significantly associated with the rate of occurrence of viral rebound (compared with zero missed doses: 1 dose, hazard ratio [HR] 1.03, 95% confidence interval [CI] 0.72-1.48; 2 doses, HR 2.17, 95% CI 1.46-3.25; >2 doses, HR 3.66, 95% CI 2.50-5.34). Several variables significantly associated with an increased risk of viral rebound irrespective of adherence were identified: being on a protease inhibitor or triple nucleoside regimen (compared with a non-nucleoside reverse transcriptase inhibitor), >5 previous cART regimens, seeing a less-experienced physician, taking co-medication, and a shorter time virally suppressed.
  
  
  CONCLUSIONS
  A simple self-report adherence questionnaire repeatedly administered provides a sensitive measure of non-adherence that predicts viral rebound.
authors.affiliation: Basel Institute for Clinical Epidemiology, University Hospital Basel, Basel, Switzerland.
authors.forename: Tracy R
authors.initials: TR
authors.lastname: Glass
authors.forename: Sabina
authors.initials: S
authors.lastname: De Geest
authors.forename: Bernard
authors.initials: B
authors.lastname: Hirschel
authors.forename: Manuel
authors.initials: M
authors.lastname: Battegay
authors.forename: Hansjakob
authors.initials: H
authors.lastname: Furrer
authors.forename: Matthias
authors.initials: M
authors.lastname: Covassini
authors.forename: Pietro L
authors.initials: PL
authors.lastname: Vernazza
authors.forename: Enos
authors.initials: E
authors.lastname: Bernasconi
authors.forename: Martin
authors.initials: M
authors.lastname: Rickenboch
authors.forename: Rainer
authors.initials: R
authors.lastname: Weber
authors.forename: Heiner C
authors.initials: HC
authors.lastname: Bucher
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage* / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000175:diagnosis* / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects* / Q000302:isolation & purification / Q000502:physiology; D006801:Humans; D007407:Interviews as Topic; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D011379:Prognosis; D015203:Reproducibility of Results; D012650:Self Disclosure; D017211:Treatment Failure
chemical_list: D019380:Anti-HIV Agents