Introduction: Developing appropriate strategies to sustain optimal medication adherence among the increasing number of HIV-positive patients taking antiretroviral therapy (ART) in sub-Saharan Africa is a major challenge.

Aims: The objective of this study was to determine patient, regimen, disease, patient-provider, and healthcare-related factors associated with adherence with ART over a one-year period, and assess the impact of adherence on treatment outcomes.

Methods: We performed a prospective, observational study among 246 patients who were initiated on ART in Ethiopia, from December 2012 through March 2013. All patients who attended 12 months’ follow-up and had completed self-reported adherence data were included in this analysis.

Results: Of 172 patients who completed follow-up, 130 (75.6%) had  95 % self-reported (combined dose and time) adherence. In multivariate analysis, lower body mass (BMI) (OR 1.2; 95% CI 1.0, 1.4) and lower HIV symptoms and adverse reaction distress scores (OR 1.1; 95 % CI 1.0, 0.9) and the use of medication reminder devices (OR, 9.1; 95% CI 2.0, 41.6) were associated with higher adherence. CD4 count increase was significantly higher in adherent patients compared to non-adherent patients at 12 months (159 cells/μL [IQR, 72-324 cells/μL] vs. 132 cells/μL [IQR, 43-190 cells/μL]; p = 0.026).

Discussion: Our findings indicate that interventions aimed at improving adherence, and thereby treatment outcomes in patients initiated on ART, should promote the use of reminder devices, as well as monitor HIV symptoms and adverse reaction distress and nutritional status.