AZT trials in developing countries (8)
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I have a slightly different take 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 under-
taken?"
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 occurring. 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 $1,000 (including any monitoring and lab
work);
Reduction of vertical transmission 24% to 8% net 16% benefit;
If we take a country with 10% HIV sero-prevalence 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 $6,562.
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 STD's is an effective way of reducing HIV transmission
and yet how many counties have been able to effectively institute ef-
fective 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 de-
veloping country health systems capacity.
So why were these trials undertaken? My assessment is that since pla-
cebo 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 justi-
fied 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
--
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
mailto:richardl@bu.edu
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