In the interests of time: improving HIV allocative efficiency modelling via optimal time‐varying allocations

Abstract

IntroductionInternational investment in the response to HIV and AIDS has plateaued and its future level is uncertain. With many countries committed to ending the epidemic, it is essential to allocate available resources efficiently over different response periods to maximize impact. The objective of this study is to propose a technique to determine the optimal allocation of funds over time across a set of HIV programmes to achieve desirable health outcomes.MethodsWe developed a technique to determine the optimal time-varying allocation of funds (1) when the future annual HIV budget is pre-defined and (2) when the total budget over a period is pre-defined, but the year-on-year budget is to be optimally determined. We use this methodology with Optima, an HIV transmission model that uses non-linear relationships between programme spending and associated programmatic outcomes to quantify the expected epidemiological impact of spending. We apply these methods to data collected from Zambia to determine the optimal distribution of resources to fund the right programmes, for the right people, at the right time.Results and discussionConsidering realistic implementation and ethical constraints, we estimate that the optimal time-varying redistribution of the 2014 Zambian HIV budget between 2015 and 2025 will lead to a 7.6% (7.3% to 7.8%) decrease in cumulative new HIV infections compared with a baseline scenario where programme allocations remain at 2014 levels. This compares to a 5.1% (4.6% to 5.6%) reduction in new infections using an optimal allocation with constant programme spending that recommends unrealistic programmatic changes. Contrasting priorities for programme funding arise when assessing outcomes for a five-year funding period over 5-, 10- and 20-year time horizons.ConclusionsCountries increasingly face the need to do more with the resources available. The methodology presented here can aid decision-makers in planning as to when to expand or contract programmes and to which coverage levels to maximize impact.

The global Optima HIV allocative efficiency model: targeting resources in efforts to end AIDS

“…We expect this limitation to most affect funding for VMMC in generalized epidemic settings, as shown by Shattock et al 24 for South Africa. Seventh, for the optimization scenario whereby international funds were permitted to be shifted between countries, we assumed that redistribution would not be limited to investment in select programme(s), as is often specified by some funding organizations.…”

Sensitivity of joint contagiousness and susceptibility-based dynamic optimal control strategies for HIV prevention

“…The methods we have developed and employed in this paper are based on the mathematics of control theory that has been used to address epidemiological resource allocation problems since the 1970s [ 6 ]. However, much of the research applying control theory to epidemiologic problems has focused on purely theoretical concerns [ 7 – 9 ], calculated the optimal allocation strategy for very general settings [ 10 – 16 ], or assumed a strong a priori form to the control [ 17 ]. Studies where the underlying model and choice of parameters were tailored to a specific setting [ 18 , 19 ] were less frequent than general studies.…”

Frontloading HIV financing maximizes the achievable impact of HIV prevention

“…Indeed, other modelling studies suggests that immediate rapid expansion of efforts, particularly until 2020, will be critical to meeting the goal of ending the epidemic by 2030 . At the national level, modelling studies have also found that intensifying investment in prevention and treatment immediately will be most impactful . Intensifying the response is critical as the large and growing treatment costs are, in some places, already at the same scale as national debt, with needs exceeding the projected HIV fiscal space in the long‐term .…”