Second-line antiretroviral therapy in a workplace and community-based treatment programme in South Africa: determinants of virological outcome.
BACKGROUND
As antiretroviral treatment (ART) programmes in resource-limited settings mature, more patients are experiencing virological failure. Without resistance testing, deciding who should switch to second-line ART can be difficult. The consequences for second-line outcomes are unclear. In a workplace- and community-based multi-site programme, with 6-monthly virological monitoring, we describe outcomes and predictors of viral suppression on second-line, protease inhibitor-based ART.


METHODS
We used prospectively collected clinic data from patients commencing first-line ART between 1/1/03 and 31/12/08 to construct a study cohort of patients switched to second-line ART in the presence of a viral load (VL) ≥ 400 copies/ml. Predictors of VL<400 copies/ml within 15 months of switch were assessed using modified Poisson regression to estimate risk ratios.


RESULTS
205 workplace patients (91.7% male; median age 43 yrs) and 212 community patients (38.7% male; median age 36 yrs) switched regimens. At switch compared to community patients, workplace patients had a longer duration of viraemia, higher VL, lower CD4 count, and higher reported non-adherence on first-line ART. Non-adherence was the reported reason for switching in a higher proportion of workplace patients. Following switch, 48.3% (workplace) and 72.0% (community) achieved VL<400, with non-adherence (17.9% vs. 1.4%) and virological rebound (35.6% vs. 13.2% with available measures) reported more commonly in the workplace programme. In adjusted analysis of the workplace programme, lower switch VL and younger age were associated with VL<400. In the community programme, shorter duration of viraemia, higher CD4 count and transfers into programme on ART were associated with VL<400.


CONCLUSIONS
High levels of viral suppression on second-line ART can be, but are not always, achieved in multi-site treatment programmes with both individual- and programme-level factors influencing outcomes. Strategies to support both healthcare workers and patients during this switch period need to be evaluated; sub-optimal adherence, particularly in the workplace programme must be addressed.
Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom. victoria.johnston@lshtm.ac.uk
Victoria
V
Johnston
Katherine
K
Fielding
Salome
S
Charalambous
Mildred
M
Mampho
Gavin
G
Churchyard
Andrew
A
Phillips
Alison D
AD
Grant
D000328:Adult; D019380:Anti-HIV Agents / Q000494:pharmacology*; D005260:Female; D006678:HIV / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000706:statistics & numerical data; D012111:Residence Characteristics / Q000706:statistics & numerical data*; D013019:South Africa; D016896:Treatment Outcome; D019562:Viral Load / Q000187:drug effects; D028761:Withholding Treatment / Q000706:statistics & numerical data; D017132:Workplace / Q000706:statistics & numerical data
D019380:Anti-HIV Agents