Understanding and optimising HIV prevention and related outcomes among serodiscordant couples in Africa
File(s)
Author(s)
Jewell, Britta
Type
Thesis
Abstract
Daily oral tenofovir-based pre-exposure prophylaxis (PrEP) has recently been shown
to be an efficacious HIV prevention strategy for key populations at high risk of acquiring
HIV-1, including serodiscordant couples. This thesis addresses the following research
question: what is the projected impact and cost-effectiveness of PrEP for serodiscordant
couples in sub-Saharan Africa, and would it be a worthwhile intervention? By using
statistical analysis and mathematical modelling, I answer this question and provide
recommendations for the optimisation of antiretroviral-based HIV prevention this population.
In this thesis, I begin by exploring the effect of the reduced risk of herpes simplex
virus type 2 (HSV-2) acquisition by means of PrEP on the outcomes of an intervention, but
conclude that the supplementary benefit is unlikely to substantially alter the costeffectiveness.
I also perform statistical analysis of daily adherence patterns to PrEP,
according to electronic monitoring, from the Partners PrEP Study and the Partners
Demonstration Project in Kenya and Uganda and find that adherence was high in both
settings. Finally, I adapt a microsimulation model of serodiscordant couples in Africa to
include realistic PrEP adherence patterns, HIV-1 transmission, external partnerships, and
empirical costs. Using this model, I simulate the likely impact and cost-effectiveness of a
PrEP intervention according to characteristics and behaviours of couples in the context of a
clinical trial and a demonstration project. Overall, I conclude that a PrEP intervention could
be cost-effective or cost-saving when targeted to high-risk couples, but is unlikely to be cost-effective
if expected incidence is low. In addition, the utility of PrEP for serodiscordant
couples could be compromised if the resources needed to find high-risk couples are
expensive or if couples are not found easily.
to be an efficacious HIV prevention strategy for key populations at high risk of acquiring
HIV-1, including serodiscordant couples. This thesis addresses the following research
question: what is the projected impact and cost-effectiveness of PrEP for serodiscordant
couples in sub-Saharan Africa, and would it be a worthwhile intervention? By using
statistical analysis and mathematical modelling, I answer this question and provide
recommendations for the optimisation of antiretroviral-based HIV prevention this population.
In this thesis, I begin by exploring the effect of the reduced risk of herpes simplex
virus type 2 (HSV-2) acquisition by means of PrEP on the outcomes of an intervention, but
conclude that the supplementary benefit is unlikely to substantially alter the costeffectiveness.
I also perform statistical analysis of daily adherence patterns to PrEP,
according to electronic monitoring, from the Partners PrEP Study and the Partners
Demonstration Project in Kenya and Uganda and find that adherence was high in both
settings. Finally, I adapt a microsimulation model of serodiscordant couples in Africa to
include realistic PrEP adherence patterns, HIV-1 transmission, external partnerships, and
empirical costs. Using this model, I simulate the likely impact and cost-effectiveness of a
PrEP intervention according to characteristics and behaviours of couples in the context of a
clinical trial and a demonstration project. Overall, I conclude that a PrEP intervention could
be cost-effective or cost-saving when targeted to high-risk couples, but is unlikely to be cost-effective
if expected incidence is low. In addition, the utility of PrEP for serodiscordant
couples could be compromised if the resources needed to find high-risk couples are
expensive or if couples are not found easily.
Version
Open Access
Date Issued
2015-09
Date Awarded
2015-12
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Hallett, Timothy
Cremin, Ide
Pickles, Michael
Publisher Department
School of Public Health
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)