Too often, the evidence available for public health practice is generated and applied through separate, nonoverlapping processes. Researchers, often relying on well-funded and professionally staffed grants, are responsible for generating evidence for effective interventions. This intervention evidence (the “push”) is then handed off to practitioners and policy makers who are charged with implementing a program or policy (the “pull”). As noted by Green, if we are seeking to foster evidence-based practice, we need more practice-based evidence (7) (ie, evidence developed in real world settings via partnerships between practitioners and researchers).

This type of practice-based research is more likely to take into account the important concept of context — the difficult-to-measure characteristics of the agency; the community; and the sociocultural, political, or economic surroundings in which an intervention is to be implemented, adapted, or evaluated (1). Contextual factors have an effect on external validity (ie, the degree to which findings from a study or set of studies can be generalizable to and relevant for populations, settings, and time periods other than those in which the original studies were conducted) (8). Practice-based research satisfies one or more of the following principles: 1) use of participatory research approaches to engage stakeholders in identifying study topics; 2) evaluation of ongoing program and policies (sometimes called natural experiments); 3) placement of greater emphasis on external validity; 4) use of new networks for conducting research (eg, practice-based research networks); and 5) use of systems science methods to understand the complexity and context underlying public health issues. The articles in this issue clearly illustrate the value of practice-based research.

A core issue facing dissemination and implementation research involves the concept of how adapting an intervention influences effectiveness. Although the evidence base on effective chronic disease interventions has grown enormously in the past few decades, knowledge about how to adapt, implement, and evaluate interventions is lacking for many settings and populations. A key challenge when adapting an intervention is the tension between fidelity (keeping the key ingredients of an intervention that made it successful) and adaptation (the ability to fit the community or setting of interest). Adapting interventions from one setting to another requires considerations regarding the extent to which the determinants of the issue are comparable (which determines whether the intervention focus is or is not appropriate) and how contextual differences (eg, political environment, health care systems) may affect the intervention. Lee and colleagues developed a useful approach for planned adaptation that includes 4 steps: 1) examining the evidence-based theory of change, 2) identifying population differences, 3) adapting the program content, and 4) adapting evaluation strategies (9).

Participatory research methods have the potential to address chronic diseases by involving community members and stakeholders in the decision-making processes, thus enhancing the relevance and overall quality of research. Within community and public health settings, participatory research builds trust, respect, capacity, empowerment, accountability, and sustainability (10), all of which are critical to improving the intervention’s chances for success. This process has tremendous potential for testing the effectiveness of interventions and for disseminating EBPH. As illustrated in the articles in this collection, community engagement and participation can play roles across a wide spectrum, ranging from engaging consumers, patients, or practitioners as advisors, to hiring research staff from communities of focus, to full participation from community members in all research activities. In taking these steps, researchers will better recognize the practical application of their scientific findings. The most effective strategies to bridge the gap between research and practice are likely to have at their heart effective partnerships between academicians, practitioners, and policy makers.

Effective dissemination and implementation of evidence-based interventions is a formidable challenge. In part, this is due to differing priorities. For researchers, the priority is often on discovery (not application) of new knowledge; whereas for practitioners and policy makers, the priority is often on practical ways of applying these discoveries in their settings. Research on how to disseminate evidence-based interventions has now taught us several important lessons: 1) multicomponent, active strategies are often the most effective; 2) leadership matters but is not sufficient; 3) provider behavior is difficult to change and (when changed) is even harder to sustain; and 4) systems are complex and change is recursive. Yet most of these lessons have been learned from studies with early adopters in high-resource settings. We have yet to learn the lessons of how to change public health in more challenging settings. Several articles in this collection take on that challenge.

These articles lead to areas where additional research is warranted, for example —

Many of these challenges need particular attention in settings with high health-related disparities where system and resource constraints are great and where delivery systems are underdeveloped.

Public health history teaches us that a long latency period often exists between the scientific understanding of a viable disease control method and its widespread application on a population basis. By expanding the evidence base for public health and applying the evidence already in hand, we can shorten the latency period and begin to fully achieve the promise of prevention. In the current era of level or shrinking public health budgets, it is more important than ever to increase the effectiveness and efficiency of public health services by applying the principles of EBPH.