1.1 Background
A collaborative research project between UNAIDS and London
School of Hygiene and Tropical Medicine, has been working since 1994 to develop
methodologies to determine the costs and likely impact of a range HIV prevention
strategies - the strengthening of blood transfusion services, the strengthened
distribution of condoms, school education, the strengthening of sexually
transmitted disease (STD) treatment services, interventions working with sex
workers and their clients, and interventions working with injecting drug users.
HIVTools: a cost-effectiveness toolkit for HIV
prevention is currently being developed. HIVTools consists of 1) a
set of five simulation models that estimate the impact on HIV and STD
transmission of different HIV prevention activities, and 2) guidelines for
costing different HIV prevention activities. HIVTools can be used to
estimate the impact, cost and cost-effectiveness of different HIV prevention
strategies in different settings.
Blood 3.0 is one of the models within HIVTools. It
has been developed to estimate the impact of different HIV prevention
activities. Blood 3.0 can be used, within a particular setting, to obtain
estimates of the impact of interventions to strengthen the delivery of blood
transfusion services. It can also be used to explore what may be the likely
impact of different policy options. Estimates of the extent to which the
strengthening of blood transfusion services may avert HIV infection among the
main recipients of blood products are obtained by comparing the projected number
of HIV infections estimated to have occurred in a particular year, if the
intervention had not been implemented, with the projected number of HIV
infections estimated to have occurred in the presence of the intervention.
Comparisons are made using information on the pre and post intervention patterns
of blood collection, testing and transfusion.
From conception, the aim was to develop a simple tool that could
be used to provide applied intervention specific insights of use to Program
Managers and policy makers at the national and local level. For this reason, the
structure of Blood 3.0 has been geared towards using the routine forms of
monitoring and evaluation data currently being collected by blood transfusion
services. It is hoped that this approach can be used to improve understanding of
the impact blood transfusion services, and the potential impact of different
forms of possible changes in blood collection, testing and transfusion
practice.