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The Program Science initiative: improving the planning, implementation and evaluation of HIV/STI prevention programs
  1. Sevgi O Aral1,
  2. James F Blanchard2
  1. 1Division of STD Prevention, The National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
  2. 2Department of Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
  1. Correspondence to Dr Sevgi O Aral, Division of STD Prevention, The National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention Centers for Disease Control and Prevention, 1600 Clifton Road, Mailstop E-02, Atlanta, GA 30333, USA; soa1{at}


In this article, the authors describe the Program Science initiative in detail, discuss some of its recent accomplishments and explore its significance and timeliness in light of the HIV prevention challenges. The authors also describe the Program Science series being launched and present a preview of future articles.

  • Program Science
  • implementation science
  • complexity
  • combination interventions
  • STD
  • HIV
  • social/policy perspectives
  • social
  • heterosexual BEH
  • sociology
  • behavioural interventions
  • epidemiology
  • public health

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The past few years have been marked by exciting developments in HIV prevention. Biomedical interventions including male circumcision, microbicides, pre-exposure chemoprophylaxis and early anti-retroviral therapy have been shown to effectively prevent acquisition and transmission of HIV.1–6 However, challenges remain. Implementation and scale-up of efficacious interventions, at the population level, continue to prove difficult. The field has acknowledged the need for combination prevention strategies,7 but the choice of specific strategies and interventions to be included in such intervention packages remains challenging. The highly complex interactions among interventions8 and between interventions and the context in which they are introduced9 render such choices difficult. Moreover, recent economic trends and the resultant declining public health resources have magnified the salience of the cost of HIV prevention. More than ever before, now choices have to be made among interventions and between prevention strategies. Even in developed countries, prevention resources are limited and declining. In the developing world the economics of HIV prevention may be at least as important as prevention efficacy.

The global HIV prevention experience over the past 30 years has been challenging. A recent review has identified five factors as being responsible for the challenges.10 These include: the limited arsenal of effective interventions; the difficulty involved in implementing effective prevention interventions at sufficient scale and intensity relative to the need; the scattering of interventions across geographical areas and the resulting inability to realise synergies that multiple interventions in one location would lead to; the insufficient targeting of interventions to key affected populations, especially in concentrated and mixed epidemics; and the lack of linkages between prevention services and other prevention, care and treatment services, and across clinical and community-based settings.

In response to the above challenges, the most recent guidance (August 2011) for the US President's Emergency Plan for AIDS Relief10 emphasises the importance of knowing the epidemic, the context, the response and the costs. It is noted that in every national and subnational context, there may be prevention investments that are more effective in reducing HIV than others.

In a recent article in this journal, Blanchard and Aral11 described a nascent initiative—Program Science—which intends to provide a framework that both expands the scope for knowledge development and provides an interface between program and science focused on resolving program issues.

The Program Science initiative maintains that: the impact of programs for the prevention of HIV and STI can be improved by closing the program–science gap; the standard model of knowledge translation involves generating scientific evidence in support of single interventions and efforts to ensure that this evidence is used in practice; and proposes to address the complexity of program design, implementation and evaluation, thereby bringing about better integration between program implementers and scientists.

With the current issue, the journal Sexually Transmitted Infections is launching a new series of invited articles on the Program Science initiative, its concepts, methodologies and practical applications. In this article, we describe the Program Science initiative in more detail, discuss some of its recent accomplishments and explore its significance and timeliness in light of the HIV prevention challenges mentioned above. We also describe the Program Science series being launched and present a preview of future articles.

The initiative

Perhaps the best definition of Program Science is the systematic application of theoretical and empirical scientific knowledge to improve the design, implementation and evaluation of public health programs.11 Population level impact on the incidence of infections constitutes the end point for Program Science. Its approach is the optimisation of the choice of the right strategy for the right populations at the appropriate time; the implementation of the right things the right way; and the achievement of appropriate scale and efficiency. Program Science focuses on the development, implementation and continuous improvement of the prevention program in its totality. Thus, Program Science includes issues of resource allocation, maximisation of return on investment, definition and prioritisation of target populations, development and prioritisation of intervention packages, identification of stopping rules to prevent indefinite implementation of interventions beyond the cessation of their usefulness, as well as the design, optimal implementation and coverage of combination intervention packages. Also included in Program Science are development and application of program impact evaluation methods that take account of the complex interactions among interventions and between intervention packages and the context into which they are introduced. Moreover, policy interventions, advocacy and community mobilisation in support of prevention interventions also are within the scope of Program Science. A variety of knowledge spheres including epidemiology, transmission dynamics, policy analysis, intervention efficacy and effectiveness, surveillance, operations research and monitoring and evaluation; and a variety of practice spheres including strategic planning and policy development, program implementation and program management comprise the expertise base supporting Program Science.

The Program Science initiative was launched in early May 2010 during an inaugural meeting of researchers, prevention program implementers, policy makers and funders, with support from the office of AIDS Research of the National Institutes of Health. Experts addressed key Program Science components and the evidence base for Program Science including mathematical modelling, complexity science, implementation science, health systems research and impact evaluation during the meeting.

Since its launch the Program Science initiative has accomplished a number of objectives and the network of researchers and program experts involved in the initiative has expanded considerably. A core group of distinguished scientific advisors has been established—their names can be found on the journal's website in supplementary materials for this article. Three scientific meetings have been held focusing on a variety of topics including issues of assessment, targeting, coverage, monitoring and evaluation, program management, resource allocation and maximisation of return on investments. Seven invited symposia were organised during national and international scientific meetings, including the International Society for STD Research in June 2011 and the International AIDS Society Conference in July 2011, focusing on the specific topics mentioned above.

Three country-level Program Science initiatives have been established in Nigeria, Kenya and India to date. Three additional country-level initiatives are now under consideration, one in Africa and two in Asia. The country programs demonstrate the functioning of the Program Science initiative on the ground with embedded scientists, program managers and program implementers working closely together. At this stage the country programs focus on assessments and issues of choice of intervention mix, prioritisation of target populations and allocation of resources. During later phases, issues of monitoring and evaluation and stopping rules are expected to gain greater prominence.

In addition to prevention scientists and program experts, policy makers have shown particular interest in the Program Science initiative. Senior experts from the World Bank, the Bill and Melinda Gates Foundation and the Centers for Disease Control and Prevention (CDC) have participated actively in all scientific meetings. Furthermore, the World Bank and the Bill and Melinda Gates Foundation have provided major funding for specific components of the initiative. The National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention (NCHHSTP) at CDC has announced Program Science to be one of the National Center's priorities; and the Division of Sexually Transmitted Disease Prevention at CDC is currently developing a Program Science application initiative.

The timing and significance of the Program Science initiative

The present is a particularly interesting time in public health in general and in the prevention of sexually transmitted disease (STD) and HIV in particular. Efficacious prevention technologies are available for the prevention of STDs, and more recently HIV. Resources, and particularly financial resources, are constrained and in many contexts, declining.

While we now have within our armamentarium the tools that, if implemented appropriately and adhered to adequately, can turn around the dynamics of the global HIV pandemic, appropriate implementation and adequate adherence are going to provide serious challenges. Similarly, the recent international financial crises and the mounting efforts to control public spending and debt, exert growing pressure on traditional funding channels for global health. Consequently, greater attention is now being paid to innovative financing mechanisms.12 In this context, strategic planning and execution of prevention programs is of central importance. Past and current investments in HIV science have resulted in our potential ability to save lives and prevent infections. Future investments in Program Science can enable us to actualise these lifesaving gains; they will also help us maximise returns on our HIV prevention investments.

At this time, program expertise which would dictate what to do, when and how, seems to be limited. A great number of key questions remain difficult to answer including: when to target which subpopulations; how to reach particular subpopulations; which interventions to use at which intensity, for which duration, at what scale, in which sequence; which interventions to combine; when to stop a particular prevention strategy; which parameters to monitor; how to identify the phase an epidemic is in; how to choose interventions in light of the local cost structure; how to balance the costs and benefits of preventive interventions; and how to maximise the return to prevention investments.

What is needed is a strategic planning approach which considers all of the above questions and other related issues as a whole in their totality, and takes into account the mutual impact(s) of different decisions/actions on each other. Consideration of issues of synergies, antagonisms and unintended consequences constitute an important component of such planning. Moreover, the epidemiological, economic and socio political context(s) enter these interaction networks and play a major role which needs to be taken into account. Even when a program develops a perfect strategic plan, with all key questions answered and all interactions, consequences and contextual factors considered, the work is barely started.

Implementation of intervention packages and monitoring and evaluation activities poses a different challenge. Available health systems through which programs need to work can be limited and overloaded. Public health personnel may have limited education and training. Fidelity to efficacious interventions may be lacking, or conversely, implementers may remain faithful to a standardised intervention when the context calls for modifications and adjustments. Quality of interventions may prove difficult to maintain. Finally, allocation of resources to various intervention implementation activities may be problematic with most resources being spent on initial activities and remaining resources proving inadequate for later needs.

The sexually transmitted infections Program Science series

In response to the need in the field for Program Science expertise, the journal has initiated the publication of a series of articles in this domain and asked Drs Sevgi O Aral and James F Blanchard to serve as editors for the series. This article is the first in the series and provides an overall description of Program Science and the Program Science initiative as it stands now. The series includes twelve invited articles to appear in the next 12 issues of the journal. The invited authors are highly prominent scientists in their fields. The articles will cover a wide variety of topics central to the field of Program Science. These will include issues related to the introduction of new technologies into new contexts, issues of cost and cost effectiveness, impact evaluation methodologies, uptake of male circumcision, importance of discordant couples in HIV prevention, categorisation of STI/HIV epidemics, importance of context and coverage, and the ‘Avahan’ business model. In addition, the series will include three papers each of which describes a Program Science country program in Nigeria, Kenya and India.

We hope this series of articles will initiate sufficient interest and dialogue in the field so as to lead to a permanent column on Program Science in the journal. To facilitate discussion on the topic we will organise podcasts and blogs to accompany the publications. The need for enhanced and widespread expertise in Program Science is glaring. The publication of this series of articles can help fulfil this need at least in part.


The authors thank Patricia Jackson for her outstanding support in the preparation of this article.



  • Disclaimer The findings and conclusions in this paper are those of the author(s) and do not necessarily represent the views of the Centers for Disease Control and Prevention.

  • Competing interests None.

  • Provenance and peer review Not commissioned; externally peer reviewed.