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

Background: 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.

Methods: 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.

Results: 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).

Conclusion: 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.