Page 91 - UCT2012 Research Report

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Poverty and Inequality
Economics of Tuberculosis
Over the years, the HEU has undertaken various economic
evaluations of interventions to address key public-health
challenges.
Research Projects
Social Determinants of
Health
In 2005, the World Health Organisation launched the
Commission on Social Determinants of Health (SDH). This
was intended to explore ways of tackling increasing health
inequalities both within and across countries, through
actions around the social determinants of health.
At present, a major focus is on TB interventions. The
XTEND study is evaluating the cost-effectiveness of
the new TB diagnostic technology Xpert MTB/RIF in
the context of the national roll-out of this technology
in South Africa. This study will determine the cost-
effectiveness of Xpert MTB/RIF from a patient and
programme perspective, and will use mathematical
modelling to predict the likely population-level impact
on TB transmission. A sub-study, called XPHACTOR,
will identify an evidence-based algorithm, which is
feasible to implement within HIV clinics, to guide the
utilisation of TB diagnostic investigations. The results
will complement the XTEND study, and provide
evidence to guide the rational use of Xpert MTB/
RIF in South Africa and other settings where HIV
and TB are both prevalent. Another study under
way explores the cost-effectiveness of adding the
MVA85A vaccine to the BCG vaccine in children from
the perspective of the South African government.
The recently published results of the Phase IIb clinical
trial conducted in Worcester, South Africa, showed
the efficacy of the MVA85A vaccine in preventing
TB in infants to be 17.3%, making the vaccine
essentially ineffective. This has a noticeable effect
on the outcomes of the cost-effectiveness analysis.
However, a Markov model that has been developed
for this vaccine could also be used to determine the
cost-effectiveness of other new TB vaccines being
tested in infants.
Broadly, theSDH include the social, political, economic,
environmental and cultural factors that affect health
status. In order to address social determinants, there
is a need to compile scientific evidence on the SDH
both within and across countries. In South Africa,
as in many other African countries, such evidence
is sparse. The Health Economics Unit is currently
compiling existing global and domestic evidence on
social determinants of health (broadly defined) both
at disease-specific level and for health in general.
Specific disease conditions that are currently being
explored include malnutrition in children, obesity,
diabetes, hypertension and mental health. Based
on this synthesised evidence and the broad WHO
framework for SDH, the HEU is developing a
conceptual framework for more fully understanding
the causal pathways and mechanisms through which
SDH operate within the South African context. The
ultimate goal is to inform domestic policy actions
that can address key social determinants (e.g. through
macro-economic and social policies) and improve
population health status.