Starting HIV treatment early, when CD4 cell counts fell below 350 cells/mm3 in
accordance with current World Health Organization (WHO) recommendations, was
cost-effective compared to starting at 200 cells/mm3 (standard ART)
over a three-year period in Haiti, American and Haitian researchers report in
the September 11 edition of PLoS Medicine.
Haiti is one of the
world’s poorest countries, lying in the bottom 10% of countries by GDP per
capita in 2010. It is the poorest nation in the western hemisphere.
Serena
P Koenig and colleagues did a cost-effectiveness study of early compared to
standard ART using data from a prospective randomised trial (CIPRA HT-001). The
trial was undertaken in 2009 at the Center of the Haitian Group for the Study
of Kaposi’s Sarcoma and Opportunistic Infections (GHESKIO) among HIV-infected
patients with a CD4 cell count between 200 and 350 cells/mm3.
The
trial showed early ART compared to standard ART reduced death rates by 75%
after a median follow-up of 21 months.
After
three years the total cost of saving one life by starting ART early rather than
waiting until the CD4 cell count was under 200 cells/mm3 was
US$2,050 with research-related costs excluded (95% CI:
US$722/YLS-US$5,537/YLS).
WHO’s
formula for the cost-effectiveness of a medical intervention is defined as less
than three times a country’s gross domestic product (GDP) for each person for
each disability-adjusted life year saved (DALY) and very cost-effective if
under one times the GDP.
The
authors used years of life saved (YLS) rather than DALY and note YLS is
generally acceptable in this formula. The threshold in Haiti in 2009
was US$2,355/YLS. The GDP for each
person in Haiti
is US$785.
In
November 2009 based on the results of the CIPRA HT-001 trial together with a
post hoc analysis within the SMART trial WHO changed its guidelines for
starting ART to when CD4 cell counts fell below 350 cells/mm3 rather
than 200 cells/mm3. The panel responsible for the recommendations
“placed a high value on avoiding death, disease progression and HIV
transmission over and above cost and feasibility.”
At
the end of 2009 in low- and middle-income countries an estimated 14.5 million
were in need of ART yet only 5.3 million were getting it; and in Haiti, with an
estimated prevalence of 2.2%, an estimated 43% (26,000) of people with CD4 cell
counts below 350 cells/mm3 were on ART.
Policy
makers in low- and middle-income countries have to make difficult decisions in
how to allocate and make the best use of limited resources.
Putting
the guidelines into practice will be determined in large part by knowing whether
it is cost-effective.
The
authors, in what they believe to be the first analysis of its kind, compared
the costs and survival benefits of early to standard ART using data from a
randomised clinical trial (CIPRA HT-001) that compared these two strategies in
HIV-infected adults with no history of an AIDS-defining illness and a CD4 cell
count between 200 and 350 cells/mm3.
Data
included: use and costs of ART and other medications, laboratory tests,
outpatient visits, radiographic studies, procedures and hospital services.
Among
816 participants enrolled between 2005 and 2008, the authors determined cost
for each year of life saved including patient and caregiver costs, with a
median of 21 months and a maximum of three years of follow-up.
During
the trial mean total costs for each patient in the early arm were US$1,381 and
US$1,033 for standard ART. When research-related costs were excluded and
clinical benefit not taken into account, the costs were US$1,158 and US$979,
respectively.
While
early ART had higher mean ART costs (US$398 compared to US$81), those in the
standard arm had higher costs for HIV physician visits, other medications, CD4
cell counts, clinically indicated laboratory tests and radiographs (US$275
compared to US$384).
The
authors note that HIV treatment protocols, laboratory tests and medications
costs are similar to those used in other resource-poor settings, and in
particular those funded in part by PEPFAR. Their findings, they argue, can be
generalised to non-trial settings since medical services including nurse and
physician contact were comparable at GHESKIO.
The
authors note that the cost-effective ratios are conservative and biased against
early ART; the clinical benefits of early ART that extend beyond the three years
are not taken into account.
Baseline
median CD4 cell counts for the early arm compared to the standard arm at the
start of ART were 280 cells/mm3 and 166 cells/mm3,
respectively.
Studies
have shown higher baseline CD4 counts are associated with better immunological
recovery and lower mortality and conversely baseline counts under 200 are
linked to higher rates of death and disease, including tuberculosis.
The
authors note their findings are comparable to results from computer-simulation
models in South Africa and Morocco.
The
authors conclude starting ART “in HIV-infected adults with CD4 counts between
200 and 350 cells/mm3 in Haiti is cost-effective after excluding
laboratory monitoring and clinical benefit. Financial and operational resources
should be prioritised so that resource poor countries [can put the new WHO
guidelines into practice].”