MIT SCALE RESEARCH REPORT
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Research Report: ZLC-2008-4
Improving Spatial Accessibility to Antiretroviral Treatments for HIV/AIDS
Christopher Charles Carr & James Dorbor Jallah
MITGlobalScaleNetwork
For Full Thesis Version Please Contact:
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Zaragoza Logistics Center (ZLC) Edificio
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________________________________________________________
Improving Spatial Accessibility to Antiretroviral Treatments
for HIV/AIDS
Christopher Charles Carr & James Dorbor Jallah
EXECUTIVE SUMMARY
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There are 5 million people in the world in need of and without access to antiretroviral (ARV)
treatment for HIV/AIDS. An estimated 63% of people with HIV/AIDS live in Sub-Saharan
Africa (a region with 10% of the world’s population). It is estimated that the virus is directly
responsible for reducing the life expectancy of the sub-region to 47 years (from an estimated
62 years without the impact of HIV/AIDS) and for reducing the sub-region’s GDP year-toyear growth rate to 1% per year.
Over the past decade, organizations such as PEPFAR, The World Bank, and The Global Fund
have made grants - totaling billions of US dollars - directly available to the countries most
directly affected by the HIV pandemic. Organizations such as the Clinton Foundation have
also made treatment more economically feasible by providing generic ARV drugs. The
United Nations has responded to the HIV/AIDS crisis by including the halt and reversal of
the spread of the epidemic as one of its Millennium Development Goals and aiming to have 3
million people in developing countries on ARV treatment by 2005 as its “3 by 5” goal.
Despite all of these commitments, only 2 million of the 7 million people needing treatment in
developing countries were receiving it as of the end of 2007.
In the resource-constrained environments, where HIV/AIDS is most prevalent, the optimal
placement of treatment facilities has a direct effect on the number of people willing to seek
and remain adherent to ARV therapy. In order to successfully treat a patient for HIV/AIDS,
two conditions are necessary:
•
Patients must attend: Clinics must be placed in locations that patients are aware of
and willing and able to travel to for an initial consultation. A direct correlation
between the distance travelled and attendance has been observed by past studies in
different environments.
•
Patients must adhere: Because of the mutating nature of the HIV virus, patients
must be at least 95% adherent to their treatment, which has to be vigilantly monitored
by health providers. Monitoring is often enforced by having patients travel to their
facility to receive their prescription. The location of a patient’s clinic is one of many
factors that directly correlate to the patient’s successful treatment.
Executive Summary, MIT-Zaragoza Master’s Thesis, 2008
1
Improving Spatial Accessibility to Antiretroviral Treatments for HIV/AIDS
Traditional methods of optimal site location, such as Maximum Capture (MaxCap), fail to
take into account population-specific factors and thus lead to significant sub-optimal results.
By taking into account factors such as non-homogenous HIV prevalence rates, the correlation
of distance travelled to attendance rates, and the correlation of distance travelled to adherence
rates, one can locate future clinics at sites that will be able to get more patients on treatment
and keep these patients on treatment.
Using new methods of site placement in conjunction with distance travelled to attendance and
adherence correlation data from a Tuberculosis treatment center, two trends are shown:
•
A larger “catchment zone” has negative effects: The larger the “catchment zone”
considered for future ARV treatment centers, the smaller the number of patients that
are predicted to start and adhere to treatment.
•
Data significantly optimizes location: Using the data to optimize location has
dramatic effects on the results. From similar studies, 3% more patients were
predicted to start and adhere to therapy using optimal site location of twenty sites
over traditional MaxCap placement of twenty sites.
Clearly, ARV treatment facilities must be rolled out in a way in which patients will be
successfully treated. Non-adherent treatment is non-successful treatment and will not help
stop the scourge of HIV/AIDS in developing nations. By further studying the effects of
distance on attendance and adherence - and taking into account other factors such as
prevalence rates - countries will be able to more quickly roll out HIV/AIDS treatment centers
that are truly effective.
Executive Summary, MIT-Zaragoza Master’s Thesis, 2008
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