Treatment outcomes of over 1000 patients on second-line, protease inhibitor-based antiretroviral therapy from four public-sector HIV treatment facilities across Johannesburg, South Africa

Objectives: To report predictors of outcomes of second-line ART for HIV treatment in a resource-limited setting. Methods: All adult ART-naïve patients who initiated standard first-line treatment between April 2004 and February 2012 at four public-sector health facilities in Johannesburg, South Africa, experienced virologic failure and initiated standard second-line therapy were included. We assessed predictors of attrition (death and loss to follow-up [≥3 months late for a scheduled visit]) using Cox proportional hazards regression and predictors of virologic suppression (viral load <400 copies/ml ≥3 months after switch) using modified Poisson regression with robust error estimation at 1 year and ever after second-line ART initiation. Results: A total of 1236 patients switched to second-line treatment in a median (IQR) of 1.9 (0.9-4.6) months after first-line virologic failure. Approximately 13% and 45% of patients were no longer in care at 1 year and at the end of follow-up, respectively. Patients with low CD4 counts (<50 vs. ≥200, aHR: 1.85; 95% CI: 1.03–3.32) at second-line switch were at greater risk for attrition by the end of follow-up. About 75% of patients suppressed by 1 year, and 85% had ever suppressed by the end of follow-up. Conclusions: Patients with poor immune status at switch to second-line ART were at greater risk of attrition and were less likely to suppress. Additional adherence support after switch may improve outcomes.