Adherence to highly-active antiretroviral therapies in HIV-infected veterans

Abstract

Objective. To describe patient variables associated with adherence to Highly Active Antiretroviral Therapies (HAART) in the Tucson VA HIV Clinic. Methods. A cross-sectional study of sixty-seven HIV-infected veterans on HAART regimens (two protease inhibitors or three or more antiretroviral medications) examined theorized patient, patient-provider and regimen predictors related to: HIV RNA viral load, one-month monitored adherence of one antiretroviral medication within the HAART regimen via Medication Event Monitoring System cap percent therapeutic coverage (%TC-ADH), and self-reported adherence (SR-ADH). Sixty-seven subjects completed self-report, and sixty MEMS Cap data. Results. Subjects were male, white (78%), gay (54%) and/or intravenous drug using (31%), and educated (70% completed high school). Forty-three percent had an AIDS diagnosis, and antiretroviral history averaged five years. Thirty-five of sixty-seven (52%) had an HIV RNA ≤50 copies (undetectable). Forty-one of sixty (68%) had %TC-ADH ≥90%, and 41/67 (62%) had 100% SR-ADH over the previous 7 days. %TC-ADH and SR-ADH were correlated (r = .56 p < .0001). SR-ADH ≥90% was associated with an undetectable viral load (OR 3.3, CI 1.2-9.2). There was a trend toward an association between MEMS-ADH as a continuous variable and log viral load (P = 0.074). %TC-ADH ≥90% was not associated with viral suppression (OR 1.2, CI .39-3.5). Disruption of pilltaking by activities of daily living was associated with a six-fold increased risk of viral load >50 copies (OR 5.9, CI 1.4-24.8). Belief in one's ability to take medication as ordered (OR 32 CI 4.4-234) was highly associated with SR-ADH ≥90%. Employment was associated with lower odds of SR-ADH ≥90% (OR 0.12, CI .02-.67). Non-white subjects had lower odds of %TC-ADH ≥90% (OR 0.18, CI .04-.93). A 10-point higher score on the HIV-MOS energy/fatigue scale (OR 1.46, CI 1.04-2.4), and belief in ability to take medication as ordered (OR 2.5, CI 1.20-5.0), were associated with greater odds of %TC-ADH ≥90%. Conclusions. SR-ADH was associated with HIV RNA viral load. Less than 62% of patients adhered at ≥90% based upon SR and %TC-ADH. Disruption of medication-taking by activities of daily living, and poor self-efficacy may negatively affect adherence. Assessment of patient beliefs in their ability to take medications as ordered may be a clinically useful adherence screening question.