E-DRUG: AZT trials in developing countries (contd.)
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I have a slightly different views on the ethical issues related
to the controversy about the AZT trials.
I would ask "Is it ethical to undertake trials the results of
which could not be used in the environments where the trials are
undertaken?"
Most of the studies are being undertaken in environments where
health expenditure is in the region of $5 to 20 per capita per
year. Also the World Bank has done a lot of work to assess what
the different costs of a basic public health package would be.
They estimate that between $4 and $7 per capita a major impact
would occur. But very few of these countries are able to make
these investments. These are also the countries where the AZT
trials are occuring. Could AZT ever be used in the present
economic situations?
Doing a very simple cost effectiveness analysis using the following
assumptions:
Cost per HIV screening test $10 (including counselling and follow up)
Cost per ACTG 076 regimen $1000 (including any monitoring and lab work)
Reduction of vertical transmission 24% to 8% net 16% benefit
If we take a country with 10% HIV seroprevalence we would need to screen
1,000 women to identify 100. Cost = $10,000
We would need to treat all 100 women Cost = 100* $1,000 = $100,000
Out of those 100 women 16 would not transmit the virus to their child.
Cost per case prevented $110,000/16 $6,875
If we use different assumptions and assume a 1% HIV prevalence the
screening costs increase to $100,000 to identify 100 women with a C/E
ratio of 1 case prevented for $12,500.
If we assume a prevalence rate of 20% the ratio becomes $6562.
Even if the drug costs were reduced by 90% the health systems that
exist could not deliver the service. We know from the Mwanza trial that
reducing STDs (Sexually Transmitted Diseases) is an effective way of
reducing HIV transmission and yet how many countries have been able to
effectively institute effective STD diagnosis and treatment programs.
So even if these trials did show that AZT was effective would it make any
difference and my answer is no. In low prevalence countries the cost of
screening to identify women would be prohibitive and in high prevalence
countries the total costs of treatment are beyond any developing country's
health systems capacity.
So why were these trials undertaken? My assessment is that since placebo
trials could no longer be conducted in US or other developed countries there
was still an interest in knowing whether cheaper regimens would be
effective. So the only people who will benefit will be people in developed
countries and the few mothers who received AZT and not placebo. A further
concern I have is what will happen to the women after the trial. Will she be
offered any follow up? Or will she be forgotten?
There was a trial in Malawi of vaginal antiseptic wash and this I thought
was a good trial because if it had shown a reduction in rates this could
have been applicable on a widespread basis to all women without
screening. Unfortunately it did not show any reduction in vertical
transmission rate. Also the Vitamin A trials could be justified in that
every pregnant women could be supplemented without screening.
But AZT trials are I think unethical for many reasons not least of which
is that their results cannot be used in the environments where the trials
are undertaken.
I look forward to comments on this alternative approach.
Richard Laing (Associate Professor)
Department of International Health,
Boston University School of Public Health,
53 Bay State Rd, Boston 02215 MA USA
Tel 1-617-353-6630
Fax 1-617-353-6330
e-mail richardl@bu.edu
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