Factors associated with non-adherence to antiretroviral therapy in the SUN study

Adherence of 95% or greater to highly active combination antiretroviral therapy is generally considered necessary to achieve optimal virologic suppression in HIV-infected patients. Understanding factors associated with poor adherence is essential to improve patient compliance, maximize virologic suppression, and reduce morbidity and mortality.

We evaluated baseline data from 528 patients taking antiretrovirals, enrolled from March 2004 to June 2006, in a multicenter, longitudinal, prospective cohort study (the SUN study). Using multiple logistic regression, we examined independent risk factors for non-adherence, defined as reporting having missed one or more antiretroviral doses in the past three days on the baseline questionnaire.

Of 528 participants (22% female, 28% black, median age 41 years, and median CD4 cell count 486 cells/mm(3)), 85 (16%) were non-adherent. In the final parsimonious multivariate model, factors independently associated with non-adherence included black race (adjusted odds ratio (aOR): 2.08, 95% confidence interval (CI): 1.20-3.60 vs. white race), being unemployed and looking for work (aOR: 2.03, 95% CI: 1.14-3.61 vs. all other employment categories), having been diagnosed with HIV ≥5 years ago (aOR: 1.95, 95% CI: 1.18-3.24 vs. being HIV-diagnosed <5 years ago), drinking three or more drinks per day (aOR: 1.73, 95% CI: 1.02-2.91 vs. drinking <3 drinks per day), and having not engaged in any aerobic exercise in the last 30 days (aOR: 2.13, 95% CI: 1.25-3.57).

Although the above factors may not be causally related to non-adherence, they might serve as proxies for identifying HIV-infected patients at greatest risk for non-adherence who may benefit from additional adherence support.