Adherence is not a barrier to successful antiretroviral therapy in South Africa.

OBJECTIVE

To determine adherence of an indigent African HIV-infected cohort initiating antiretroviral therapy (ART); to identify predictors of incomplete adherence (< 95%) and virologic failure (> 400 HIV RNA copies/ml).

DESIGN

Prospective monitoring of adherence in a poor HIV-positive cohort, attending a public sector hospital and receiving ART through phase III studies.

METHODS

Adherence to ART was determined over 48 weeks by counting tablet-returns. Logistic regression models including age, WHO HIV stage, home language, socio-economic status, complexity and type of regimen were fitted to determine predictors of incomplete adherence and virologic failure at 48 weeks.

RESULTS

289 patients were recruited between January 1996 and May 2001. Median (mean) adherence of the cohort was 93.5% (87.2%). Three times daily dosing [risk ratio (RR), 3.07; 95% confidence interval (CI), 1.40-6.74], speaking English (RR, 0.41; 95% CI, 0.21-0.80) and age (RR, 0.97; 95% CI, 0.94-0.99) were independent predictors of incomplete adherence. Socio-economic status, sex and HIV stage did not predict adherence. Independent predictors of virologic failure included baseline viral load (RR, 2.57; 95% CI, 1.57-4.22) and three times daily dosing (RR, 2.64; 95% CI, 1.23-5.66), incomplete adherence (RR, 1.92; 95% CI, 1.10-3.57), age (RR, 0.96; 95% CI, 0.92-0.99) and dual nucleoside therapy (RR, 2.69; 95% CI, 1.17-6.15).

CONCLUSION

The proportion of individuals achieving viral suppression matched results from the developing world. Speaking the same language as site staff and simplified dosing frequency were beneficial. Socio-economic status had no impact on adherence and should not be used as a limitation to ART access.