In less ill patients with HIV, the study also found that using ART was still
less expensive than medical care without ART, but only if lower cost generic
drugs rather than brand name drugs are used.
Cost-effectiveness studies
In industrialised countries, like the United Kingdom and the United States,
studies in the late 1990s demonstrated that ART was very cost-effective. ART led
to dramatic improvements in health and a shift from inpatient hospital care to
outpatient clinic visits. In addition, patients on ART underwent fewer
diagnostic procedures and needed fewer costly treatments for opportunistic
infections. Finally, ART in industrialised countries extended life, and added
years of productivity for people with HIV who were able to get back to work
again or continue working.
Until recently, there seemed to be little point in conducting similar studies
in the developing world, but in the past few years, dramatic reductions in the
cost of antiretroviral drugs has allowed the rollout of ART through the public
health sector of several resource-constrained countries, including South Africa.
South Africa's health system was already under severe stress from the impacts
of the HIV epidemic. By the year 2000, HIV-related conditions accounted for
nearly one fourth of all public hospital admissions and one eighth of the total
public health budget, and the problem is only expected to worsen. Given the
scale of the epidemic in the country, the fate of South Africa's health care
system is dependant upon how efficiently the government manages the crisis.
The trial
A team from the University of Cape Town (collaborating with researchers from
Chelsea and Westminster Hospital in London and McGill University in
Montreal) conducted a study to calculate the cost of HIV care for persons
receiving ART and a comparison group not receiving ART in order to determine the
cost-effectiveness of ART in the South African setting. The analysis also
compared clinical outcomes, in terms of disease progression and how many years
of life were gained (LYG) by the clinical stage of HIV infection (with AIDS: WHO
stage 4, and without AIDS: WHO stages 1, 2, and 3).
Subjects were drawn from the Cape Town AIDS Cohort (CTAC), a prospective
cohort study that accrued patients before ART was freely available in public
sector hospitals (between 1995 and December 2000). All of those receiving ART in
the study (292 patients: 265 without-AIDS and 27 with AIDS) were actually
participating in phase III clinical trials. These were compared to a group of
patients from the CTAC - matched for baseline WHO stage, CD4 count, age, and
socio-economic status - who received care for HIV but who were not fortunate
enough to receive ART. Hospital records were used to compare outcomes (the
number of clinic outpatient visits, days spent in the hospital, lab tests and
other costs).
The HIV care costs were based on public sector costs in the year 2000
(adjusted for inflation in 2004), using an exchange rate of 7.6 Rand to the US
dollar. For the cost of antiretroviral therapy, they used two figures:
Scenario 1) the actual cost of branded drugs to the public sector in 2004,
730 per year, and Scenario 2) the cost for generic ART that was expected to be
negotiated by the South African government, 181 per year. (This was indeed
close to the cost that was negotiated, at least for the first line nevirapine-based
regimen).
Results for people with AIDS
Patients with AIDS on ART spent a mean of 2.04 (95% CI: 1.63-2.52) days in
the hospital per patient year (PPY) compared to 15.36 (95% CI: 13.97-16.85) days
for the group not on ART. Patients on ART were more likely to utilise outpatient
services: mean outpatient visits PPY was 7.62 (95% CI: 6.81-8.49) compared to
6.60 (95% CI: 5.69-7.62) for those not on ART.
The average cost PPY of providing services to people with AIDS not on ART was
3,520 versus 1,513 for scenario 1 and 964 for scenario 2 for people with AIDS
on ART. The incremental cost per LYG was cost-saving for both scenarios.
Results for people without AIDS
Patients without AIDS on ART spent a mean 1.08 (95% CI: 0.97-1.19) days in
the hospital PPY versus 3.73 (95% CI: 3.55-3.97) for the No-ART group, and
8.71 (95% CI: 8.40-9.03) versus 4.35 (95% CI: 4.12-5.61), respectively, for
mean number of outpatient visits PPY. Average service provision PPY was 950 for
the No-ART group versus 1,342 and 793 PPY for the ART group for scenario 1 and
2, respectively, whereas the incremental cost per life-year gained (LYG) was
1,622 for scenario 1 and 675 for scenario 2.
Limitations and commentary
Current South African guidelines recommend treatment for people with HIV with
symptomatic disease and CD4 cell counts below 200. Because the study used
clinical definitions for AIDS (WHO stage 4) but not CD4 cell counts, about a
third of the patients not considered to have AIDS would have qualified for
treatment in South Africa today. It is unfortunate that a separate analysis did
divide the two groups into 'those who would qualify for treatment' today and
'those who would not.' The study noted that, indeed, CD4 cell counts were
predictive of progression (and hospitalisation) in a univariate analysis so
presumably the cost savings from ART would apply to this group as well. However,
the other two thirds of the group without AIDS would not be considered to be in
immediate need of treatment - and using ART in such patients may not be
cost-effective.
The costs in the study included were only direct costs and did not add in the
indirect or intangible costs, such as loss of productivity or quality of life
associated with HIV/AIDS. In the UK, such indirect costs can comprise between
45% and 124% of total treatment costs. Currently no such data exist in
South Africa,' the authors note, however, if these costs were all
included, it is likely that the cost-effectiveness ratio would even be more
favourable.
The researchers also had to deal with measuring a moving target, conducting
their analysis at a time when antiretroviral prices and purchasing policy were
in a state of flux. Also today's Rand is somewhat stronger (at around 6 Rand to
the US Dollar), and it's not clear how this would affect the price of
antiretroviral drugs or cost of care for people with HIV in this study.
Nevertheless, even though the actual prices are somewhat different, the most
common first-line regimen is generic and its cost is similar to what the
researchers projected. However, the most common second-line regimen, which is
anchored by the brand name protease inhibitor Kaletra, is roughly three times as
costly.
After years of inaction, the South African government finally began to
provide ART though the public sector about a year and a half ago (and negotiated
the antiretroviral drug purchasing contracts about a year later).
Yet the pace of the rollout is much slower than hoped.
The study illustrates that delay in the rollout of ART (and failure to
negotiate better drug prices) doesn't just hurt people (which ought be enough),
it can also be quite expensive. And perhaps that might motivate the government
to expedite the process.
Reference
Badri M et al. Cost-Effectiveness of Highly Active Antiretroviral Therapy in
South Africa. PLoS Medicine: 3(1) e4, 2006.
available online: http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.0030004
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