International AIDS Society


Scaling up WHO recommendations for HIV therapy in resource-limited settings: what to do first

R. Walensky1,2,3,4, R. Wood5, A. Ciaranello1,2, A. Paltiel6, S. Lorenzana1, X. Anglaret7, A. Stoler1, K. Freedberg1,4,8


The 2009 WHO HIV treatment guidelines recommend
earlier ART initiation (CD4< 350/µl vs. < 200/µl), multiple sequential ART regimens,
and replacement of first-line stavudine with tenofovir. We consider what to do first in settings
where immediate implementation of all WHO recommendations is infeasible.

We use a mathematical model and regional input
data to project clinical and economic outcomes in a South African HIV-infected
cohort (mean age 32.8y, mean CD4 375/µl). We rank - in survival and
cost-effectiveness terms - all 12 possible combinations of: 1) stavudine
replacement with tenofovir; 2) ART initiation criterion (WHO stage;
CD4< 200/µl; or CD4< 350/µl); and 3) number of ART regimens available (1 or
2). Clinical results are undiscounted; cost-effectiveness results discount life
expectancy (LE) and costs at 3%/year. The
baseline assumption is that patients receive a single, stavudine-based ART
regimen, initiatied at WHO Stage III/IV (“stavudine/WHO/one-line”).

Projected baseline
survival is 99.1m. Five-year survival is maximized by initiating ART at CD4< 350/µl
(stavudine/< 350/µl/one-line; 87% survival) compared with adding 2nd-line
ART (stavudine/WHO/two-lines; 66%) or substituting tenofovir (tenofovir/WHO/one-line;
67%). Incremental life expectancy gains
are maximized via the following stepwise programmatic additions:
stavudine/< 350/µl/one-line (124.4m); stavudine/< 350/µl/two-lines (177.7m);
and tenofovir/< 350/µl/two-lines (191.5m).
Three programs are economically efficient: stavudine/< 350/µl/one-line
(cost-effectiveness ratio $610/year of life saved [YLS]),
tenofovir/< 350/µl/one-line ($1,410/YLS), and tenofovir/< 350/µl/two-lines
($2,230/YLS). These results persist in
the face of plausible variation in efficacy and cost assumptions.

While full and immediate implementation of the WHO
recommendations is cost-effective by widely accepted international standards,
nations with very limited resources should focus first on access to CD4
count monitoring and ART initiation at CD4< 350/µl. The optimal
second step is to switch from stavudine to tenofovir. In countries with
sufficient budgets to provide second-line ART, it is neither effective nor
cost-effective to maintain stavudine in first-line regimens.

AIDS 2010 - XVIII International AIDS Conference
Abstract no. WEAE0204

Suggested Citation
"R.Walensky, et al. Scaling up WHO recommendations for HIV therapy in resource-limited settings: what to do first. : AIDS 2010 - XVIII International AIDS Conference: Abstract no. WEAE0204 "