Baseline characteristics of patients receiving second-line ART, according to programme.

1<p>Duration of viraemia was defined as (a) Patients with viral suppression on first-line ART: date of first viral load >400 copies/ml following viral suppression to date of switch, N = 237 (57.5%)^1a; (b) ART-naive patients with no viral suppression on first-line ART: date of commencing first-line ART to date of switch, N = 103 (25.0%)^1b; (c) Patients with ART-experienced pre-programme who did not achieve viral suppression on first-line ART: assumed to be ≥12months, N = 72 (17.4%). Abbreviations: IQR, inter-quartile range; VL, viral load; NRTI, nucleoside reverse transcriptase inhibitor.