Background: Adherence to antiretroviral therapy (ART) is a strong predictor of progression to AIDS and death. It remains the most important potentially alterable factor that determines treatment outcomes.

Methods: The study is a cross-sectional survey of self-reported adherence to ART and associated factors. It included a randomly selected sample of 100 adult patients who began ART between June 2006 and December 2007. A modified Adult AIDS Clinical Trials Group questionnaire was used. The analysis compared self-reported adherence levels by factor and viral load test results.

Results: Only 71 % of patients had an adherence > 95%. Poor adherence was related to changes in daily routines (being away from home [21%] and busy with other things [17%]). All patients with symptoms suggestive of clinical depression had virologic failure. More unemployed patients (50.7%) had virologic failure than did employed patients (40%) (p = < 0.05). The clinic had a tenfold increase in patient enrolment and a ninefold decline in staff-to-patient ratio, and the proportion of patients lost to follow-up doubled in the preceding four years.

Conclusion: Adherence to ART was poor. The capacity of the clinic to manage patients adequately has declined significantly. Decentralisation of ART services to primary health care facilities should be considered.