title: Predictors of antiretroviral treatment failure in an urban HIV clinic.
abstract: BACKGROUND
  Predictors of antiretroviral treatment (ART) failure are not well characterized for heterogeneous clinic populations.
  
  
  METHODS
  A retrospective analysis was conducted of HIV-infected patients followed in an urban HIV clinic with an HIV RNA measurement < or =400 copies/mL on ART between January 1, 2003, and December 31, 2004. The primary endpoint was treatment failure, defined as virologic failure (> or =1 HIV RNA measurement >400 copies/mL), unsanctioned stopping of ART, or loss to follow-up. Prior ART adherence and other baseline patient characteristics, determined at the time of the first suppressed HIV RNA load on or after January 1, 2003, were extracted from the electronic health record (EHR). Predictors of failure were assessed using proportional hazards modeling.
  
  
  RESULTS
  Of 829 patients in the clinic, 614 had at least 1 HIV RNA measurement < or =400 copies/mL during the study period. Of these, 167 (27.2%) experienced treatment failure. Baseline characteristics associated with treatment failure in the multivariate model were: poor adherence (hazard ratio [HR] = 3.44; 95% confidence interval [CI]: 2.34 to 5.05), absolute neutrophil count <1000/mm (HR = 2.90, 95% CI: 1.26 to 6.69), not suppressed on January 1, 2003 (HR = 2.69, 95% CI: 1.78 to 4.07) or <12 months of suppression (HR = 1.64, 95% CI: 1.10 to 2.45), CD4 count <200 cells/mm (HR = 1.90, 95% CI: 1.31 to 2.76), nucleoside-only regimen (HR = 1.75, 95% CI: 1.08 to 2.82), prior virologic failure (HR = 1.70, 95% CI: 1.22 to 2.39) and > or =1 missed visit in the prior year (HR = 1.56, 95% CI: 1.13 to 2.16).
  
  
  CONCLUSIONS
  More than one quarter of patients in a heterogeneous clinic population had treatment failure over a 2-year period. Prior ART adherence and other EHR data readily identify patient characteristics that could trigger specific interventions to improve ART outcomes.
authors.affiliation: Division of Infectious Diseases, Massachusetts General Hospital, Harvard Center for AIDS Research (CFAR), and Harvard Medical School, Boston, MA 02114, USA. grobbins@partners.org
authors.forename: Gregory K
authors.initials: GK
authors.lastname: Robbins
authors.forename: Brock
authors.initials: B
authors.lastname: Daniels
authors.forename: Hui
authors.initials: H
authors.lastname: Zheng
authors.forename: Henry
authors.initials: H
authors.lastname: Chueh
authors.forename: James B
authors.initials: JB
authors.lastname: Meigs
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Freedberg
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000009:adverse effects / Q000627:therapeutic use*; D044966:Anti-Retroviral Agents / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D015497:HIV-1; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011237:Predictive Value of Tests; D012367:RNA, Viral / Q000097:blood; D012189:Retrospective Studies; D017211:Treatment Failure; D014505:Urban Population
chemical_list: D019380:Anti-HIV Agents; D044966:Anti-Retroviral Agents; D012367:RNA, Viral