Predictors of antiretroviral treatment (ART) failure are not well characterized for heterogeneous clinic populations.
A retrospective analysis was conducted of HIV-infected patients followed in an urban HIV clinic with an HIV RNA measurement ≤400 copies/mL on ART between January 1, 2003, and December 31, 2004. The primary endpoint was treatment failure, defined as virologic failure (≥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.
Of 829 patients in the clinic, 614 had at least 1 HIV RNA measurement ≤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/mm3 (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/mm3 (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 ≥1 missed visit in the prior year (HR = 1.56, 95% CI: 1.13 to 2.16).
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.
From the *Division of Infectious Diseases, Massachusetts General Hospital, Harvard Center for AIDS Research (CFAR), and Harvard Medical School, Boston, MA; †Division of General Medicine, Massachusetts General Hospital, Harvard CFAR, and Harvard Medical School, Boston, MA; and ‡Laboratory of Computer Science, Massachusetts General Hospital, Harvard CFAR, and Harvard Medical School, Boston, MA.
Received for publication June 6, 2006; accepted October 3, 2006.
Supported by National Institute of Allergy and Infectious Diseases grants K01AI062435, K24AI062476, and P30AI60354 and by the Massachusetts General Hospital Clinical Research Program.
Reprints: Gregory K. Robbins, MD, MPH, Division of Infectious Diseases, Massachusetts General Hospital, 55 Fruit Street, Cox 506, Boston, MA 02114 (e-mail: email@example.com).