Monitoring of antiretroviral therapy and mortality in HIV programmes in Malawi, South Africa and Zambia: mathematical modelling study.

<h4>Objectives</h4>Mortality in patients starting antiretroviral therapy (ART) is higher in Malawi and Zambia than in South Africa. We examined whether different monitoring of ART (viral load [VL] in South Africa and CD4 count in Malawi and Zambia) could explain this mortality difference...

Full description

Saved in:
Bibliographic Details
Main Authors: Janne Estill, Matthias Egger, Leigh F Johnson, Thomas Gsponer, Gilles Wandeler, Mary-Ann Davies, Andrew Boulle, Robin Wood, Daniela Garone, Jeffrey S A Stringer, Timothy B Hallett, Olivia Keiser, IeDEA Southern Africa Collaboration
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2013-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0057611&type=printable
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:<h4>Objectives</h4>Mortality in patients starting antiretroviral therapy (ART) is higher in Malawi and Zambia than in South Africa. We examined whether different monitoring of ART (viral load [VL] in South Africa and CD4 count in Malawi and Zambia) could explain this mortality difference.<h4>Design</h4>Mathematical modelling study based on data from ART programmes.<h4>Methods</h4>We used a stochastic simulation model to study the effect of VL monitoring on mortality over 5 years. In baseline scenario A all parameters were identical between strategies except for more timely and complete detection of treatment failure with VL monitoring. Additional scenarios introduced delays in switching to second-line ART (scenario B) or higher virologic failure rates (due to worse adherence) when monitoring was based on CD4 counts only (scenario C). Results are presented as relative risks (RR) with 95% prediction intervals and percent of observed mortality difference explained.<h4>Results</h4>RRs comparing VL with CD4 cell count monitoring were 0.94 (0.74-1.03) in scenario A, 0.94 (0.77-1.02) with delayed switching (scenario B) and 0.80 (0.44-1.07) when assuming a 3-times higher rate of failure (scenario C). The observed mortality at 3 years was 10.9% in Malawi and Zambia and 8.6% in South Africa (absolute difference 2.3%). The percentage of the mortality difference explained by VL monitoring ranged from 4% (scenario A) to 32% (scenarios B and C combined, assuming a 3-times higher failure rate). Eleven percent was explained by non-HIV related mortality.<h4>Conclusions</h4>VL monitoring reduces mortality moderately when assuming improved adherence and decreased failure rates.
ISSN:1932-6203