This chapter begins by describing the scope of work for the study, then defines the terms the committee used to conduct its work, and, finally, discusses why community-based prevention is important and how it differs from other health improvement efforts. Some individuals believe the existing frameworks for valuing community-based prevention are flawed and prone to understating its benefits; others disagree or are uncertain. Committee members brought very different perspectives and areas of expertise to the discussion, with backgrounds that included public health, community health promotion, ethics, economics, workplace wellness, and government budget analysis. This report attempts the difficult task of blending those perspectives.
Four foundations—the California Endowment, the de Beaumont Foundation, the Robert Wood Johnson Foundation, and the W.K. Kellogg Foundation—asked the Institute of Medicine to convene an expert committee to develop a framework for assessing the value of community-based, non-clinical prevention policies and wellness strategies, especially those targeting the prevention of long-term, chronic diseases. The committee’s task was as follows:
- Define “community-based, non-clinical prevention policy and wellness strategies”;
- Define “value” for community-based, non-clinical prevention policy and wellness strategies;
- Analyze current frameworks used to assess the value of community-based, non-clinical prevention policies and wellness strategies, including
- the methodologies and measures used and
- the short- and long-term impacts of such prevention policy and wellness strategies on communities, including health care spending and public health; and
- If warranted, propose a new framework or frameworks that capture the breadth and complexity of community-based, non-clinical prevention policies and wellness strategies, including interventions that target specific behaviors and health outcomes.
The framework should
- consider the sources of data that are needed and available;
- consider the concepts of generalization, scaling up, and sustainability of programs; and
- address national and state policy implications associated with implementing the framework.
The committee assembled to respond to the charge from the sponsors was composed of experts spanning different disciplines ranging from economics and program evaluation to community-based providers. Over the course of this 20-month study the committee met six times in person, participated in many conference calls, and held three information-gathering workshops. During the workshops, committee members heard from members of the prevention community as well as experts in the field of valuing different types of interventions, including interventions in the fields of education and housing.
The committee’s charge directs it to define “community-based, nonclinical prevention policy and wellness strategies” and also to define “value” for these policies and strategies. Through the course of its work the committee also used several other terms that may require clarification; in such cases definitions have been given in both the text of the report and in the glossary in Appendix A.
The phrase “community-based, non-clinical prevention policy and wellness strategies” appears in the Statement of Task. This phrase has been shortened for the purposes of this report to community-based prevention.
Community-based prevention includes programs and policies that are aimed at
- preventing the onset of disease,
- stopping or slowing the progress of disease,
- reducing or eliminating the negative consequences of disease,
- increasing healthful behaviors that result in improvements in health and well-being, or
- decreasing disparities that result in an inequitable distribution of health.
Community-based prevention is not primarily based on clinical services, although it may involve services provided by health professionals in clinical settings. The charge to the committee requested that special attention be given to the prevention of long-term, chronic diseases. Such a focus does not negate the fact that other community-based prevention efforts, such as those directed at unintended and intended injuries and mental health, are also important areas for attention.
The value of an intervention, for the purposes of this report, is defined as its benefits minus its harms and costs. There is an expanded discussion of the concept of value at the end of this chapter and in Chapter 4.
Community has been defined in a variety of ways. The committee uses the term community to mean any group of people who share geographic space, interests, goals, or history. It includes the built environment, social networks, and the organizations and institutions that sustain the individual and collective life of the community. Chapter 2 contains an expanded discussion of the concept of community.
A community-based prevention program is a coordinated activity or set of activities, such as an educational campaign against smoking, improvements to the built environment to encourage physical activity, a chronic disease education and awareness campaign to improve self-management, or a combination of such interventions, that is intended to accomplish a health objective or outcome. A policy is a rule or set of guidelines, such as nutritional standards for school lunches. An intervention is an umbrella term used to mean either a program or a policy with the goal of improving health. A strategy is the method through which programs are implemented, such as television advertisements warning of the dangers of smoking, construction of a bike path, or conducting disease management workshops in churches.
Early health-promotion efforts emphasized meeting basic human needs for clean water, adequate nutrition, and shelter. In 1900 a third of all deaths
in the United States were due to pneumonia, tuberculosis (TB), diarrhea and enteritis, and diphtheria. Children suffered high rates of morbidity and mortality, with 40 percent of deaths from those four causes occurring among children under five (CDC, 1999), and children under five accounting for a third of all deaths from all causes.
Over the past century major strides were made in improving the health of the public through population-level efforts that were implemented in individual communities. The reduction in premature mortality from TB brought about by community-based prevention is a dramatic example. In 1900 mortality rates from TB were 194 per 100,000. By 1940, before antibiotics for TB were available, the rate had dropped to 46 deaths for every 100,000 people living in the United States. The decrease was due to community-level infection control measures instituted by local health departments combined with improvements in housing (including reducing the level of crowding) and better nutrition (CDC, 1999). Large-scale public health initiatives, such as public sewer projects, chlorination of public water supplies, and food safety requirements, greatly reduced the exposure of the public to infectious organisms and reduced the incidence of such diseases as cholera, typhus, and TB (Turnock, 2009).
In the mid-20th century a new approach to improving health was made possible by the development of effective antibiotics and a new generation of vaccines combined with the professionalization of medicine. Since then, society has invested substantially in clinical interventions and strategies to improve health. This investment includes everything from the training of physicians, nurses, and other health professionals to the financing of expansions of hospital capacity and the development of new drug therapies, medical devices, and surgical techniques. Researchers have developed and fine-tuned frameworks such as randomized controlled trials and cost-effectiveness analysis for assessing the value of these clinical activities.
Decent housing, clean air and water, effective sanitation, and food safety have become such a part of our culture and public infrastructure that they are no longer thought of as health endeavors. Yet, the initiatives that led to these conditions brought about dramatic improvements in health. As we begin the 21st century there is growing recognition that the next stage of improving health and preventing disease will involve a renewed emphasis on population-level, non-clinical strategies. The committee expects that in the coming decades health practitioners and scholars will propose, develop, and implement more programs and policies designed to improve health at the community level; thus, a framework to evaluate their success and to compare them to other interventions is needed.
Community-based prevention requires cultural, social, and environmental changes, much like the extensive changes in water, sanitation and housing, and nutrition that occurred in the first half of the 20th century. As discussed earlier, improving health and preventing disease does not occur solely in the patient’s examination room; it also takes place in the community of patients and their families, friends and neighbors, employers, teachers, and storekeepers. People’s socioeconomic status, social context, and physical and cultural environment influence their health both directly and, through behavioral changes and lifestyle development and reinforcement, indirectly (Box 1-1) (Adler et al., 2008; Berkman and Glass, 2000; Berkman and Kawachi, 2000). In addition, these factors can moderate and mediate the effects of clinical interventions on health (IOM, 2006).
During the second half of the 20th century, much of the focus of chronic disease epidemiology and prevention research was on individual lifestyle and behaviors, with the notable exception of tobacco control. In recent decades, however, research has demonstrated that behavioral choices are shaped and modulated by the environments in which individuals live (Adler et al., 2008; Antonovsky, 1967; Berkman and Glass, 2000; Cohen et al., 2000; Eller et al., 2008; Kawachi and Berkman, 2001, 2003; Marmot and Wilkinson, 1999; Stansfeld et al., 1999). Thus, for example, efforts to prevent obesity-related conditions might have limited success if they do not take into consideration the social and built-environment characteristics that might act as incentives or barriers to the dietary and physical activity choices that individuals make, and, indeed, recent initiatives in obesity control have been doing exactly that (e.g., Mercer et al., 2003; Sallis et al., 2006; Storey et al., 2003). Likewise, suicide, the 10th-leading cause of death among Americans, is tied to mental illness, also a long-term chronic disease that is clearly influenced by environment and social determinants (Galea et al., 2005; Huey and McNulty, 2005; Woo et al., 2012).
Clinical preventive interventions such as screening for conditions prior to the appearance of symptoms are important preventive services. For example, colonoscopies and mammograms have succeeded in identifying the potential for disease and led to early treatment to prevent occurrence. Screening, however, identifies problems that exist after the disease or its precursors are present (e.g., polyps in the colon or lumps in the breast) and is directed at individuals. Primary prevention, which addresses risk factors before disease occurs, is increasingly recognized as important (Haddix et al., 2003). It is more desirable to prevent obesity than to treat diabetes, yet delivering community-based prevention interventions is often more difficult to fund and staff than providing clinical interventions.
Disparities in Health
Chronic disease and its precursors are not distributed evenly across the population but are more likely to be present in minority and lower socioeconomic status (SES) populations (IOM, 2009, 2011). For example, significant differences in life expectancy remain between blacks and whites (CDC, 2011). Racial and ethnic disparities in health have more to do with differences in physical and social contexts than with individual biology and behavior. Some researchers have concluded that individuals’ zip codes have a greater impact on their health than their genetic codes (RWJF, 2008). For example, in 2001 Diez-Roux and colleagues found that the neighborhood of residence had an impact on the risk of coronary heart disease even after controlling for income, education, and occupation (Diez-Roux et al., 2001).
The social determinants that lead to poor health—poverty, lower levels of education, poor housing and nutrition, limited health literacy—are more likely to be present in populations marginalized by prejudice and poverty. The risk factors that arise from these determinants—obesity, tobacco and drug use, stress, depression, occupational and other environmental exposures—are also more prevalent, as are the diseases that result (RWJF, 2008).
Even when other risk factors have been accounted for, however, SES appears to have an effect on health. The Whitehall II Study of British civil servants by Michael Marmot and colleagues (1991) demonstrated that, despite universal access to health care, there was a stepwise gradient of health, with the higher-grade civil servants having better health and persons in the top ranks of Whitehall being the healthiest of all. The researchers discovered that about 20 percent of the variance in health status and life expectancy between grades could not be explained by the usual risk factors for poor health. This relationship between social status and health is referred to as the social gradient in health. Further analysis of the data on the effect of biological and behavioral factors on the risk of coronary heart disease within the Whitehall cohort showed that only about 60 percent of the social gradient could be explained by these factors (Marmot, 2004). Potential social explanations for these differences include the concepts of self-efficacy and empowerment, but uncertainty remains about the biological pathways that might underlie the influence of such social factors on health.
Policies and programs to avoid further deterioration of health or death once a person is ill are generally seen as reasonable. However, preventing illness requires that society invest the financial and other resources necessary to make the required changes in individual and community life before someone becomes sick, and this means that some of the persons who receive
the intervention—and share the costs for it—would never have become sick anyway. Thus it can be easier to make the case for improving an individual’s health, where the cost–benefit relationship is clearer, than it is to make the case for community-based prevention, especially to individuals who perceive their own risk of illness as low.
In contrast to individuals who need treatment because they are ill, those who avoid an illness due to a prevention program are not individually identifiable and thus may not realize that they have benefited. The costs of these programs are immediate, but the benefits are often deferred to the future. Furthermore, members of the community can vary in their priorities and principles. Disagreements over the merits of a program or policy objectives and disputes about the methods used to implement a program also hinder funding of some community activities.
The Concept of Value
Assessing the value of something requires first defining value conceptually and then measuring it. On both counts, community-based prevention is complex (see Box 1-2). The committee identified several conceptual issues that make defining value difficult.
Issues in Valuing Bicycle Lanes
It is not easy to value the implementation of bicycle lanes in a city. There are several benefits and costs, some of which are monetary and others of which are not.
One potential benefit, for example, is that cyclists receive enjoyment and exercise riding their bikes to work and other destinations. This may improve cyclists’ general and mental health and lower their risks of long-term chronic diseases. Also, cyclists pay less for driving and other forms of transportation. Others benefit because if cyclists drive cars less, there are fewer cars on the roads, which lowers congestion and travel times. Cycling also produces less air and noise pollution as well as fewer greenhouse gas emissions, thereby improving the environment for the entire community. Cycling may also add to community cohesion through interactions among bicyclists (Pucher et al., 2010).
However, the costs of implementing this intervention are more than just the direct costs of reconfiguring the road to construct the dedicated bicycle lanes. There are the monetary costs of operating a bicycle for the cyclists and the potential increase in the risk of injury due to cycling accidents, for example. Furthermore, the presence of cyclists imposes changes in driving habits and walking patterns that may have both benefits and costs for the drivers of cars, buses, and trucks as well as for pedestrians (de Nazelle et al., 2011).
Whose values? The value of an intervention depends on one’s perspective and on one’s beliefs and priorities. A program may have a very different value depending on whether the perspective is that of the federal budget, of a specific employer, of specific segments of society or a particular community, or of society in general. For example, the success of tobacco control is partly due to smoking restrictions in such places as workplaces, restaurants, and airplanes. To a nonsmoker with a generally positive view of regulation, such restrictions are valuable. To others, such as business owners who fear losing customers, such restrictions can be seen as harmful.
Values diverge on other dimensions as well. Consider needle exchange programs. Public health workers may support such programs because research has shown that they reduce the transmission of HIV (NIH, 1997). But others in the community may object because they view these programs as facilitating illegal drug use. Both groups want to discourage these activities but evaluate the trade-offs between the benefits and harms differently. To be successful, complex programs require the collaboration or at least cooperation of many sectors and organizations that may have differing values.
To monetize, or not to monetize. One approach to assessing the value of something is to measure, in dollar terms, its impacts in terms of benefits and costs. Some things are naturally monetized, such as the time spent by a paid community health educator. Other things are much more difficult, but not necessarily impossible, to monetize, such as the value of increased social cohesion. To some, the monetized approach allows a straightforward assessment of whether an intervention is worth undertaking. Monetization strikes others as misguided or wrong.
To summarize, or not to summarize. Policy makers crave simple summaries of a proposal’s impact—for example, how many lives will be saved and how many dollars the intervention will cost. Community-based prevention efforts are difficult to summarize since their effects can span financial, social, environmental, business, and ethical domains. The value of an intervention also depends critically on where and how well it is carried out.
In this chapter, the committee has discussed the committee charge, defined important terms, examined why community-based prevention is important and how it differs from other prevention approaches, and explored the concept and issues involved in valuing such programs and policies. Chapter 2 expands on the discussion of community, provides a brief historical perspective of community interventions, discusses four approaches to community-based prevention, reviews the models for implementation that represent the current state of the field, identifies key features
of community-based prevention, and examines issues associated with evaluating the effectiveness of such programs.
In Chapter 3 the committee examines how methods from systems science can be applied to community-based prevention, discusses how such methods can be used to clarify and quantify the relationships among variables, and identifies outcomes or domains of value for community-based prevention. Chapter 4 provides a list of elements that a framework for assessing value should possess, examines how a framework for valuing resides within a decision-making context, reviews eight frameworks currently used to assess community-based prevention, and discusses the strengths and limitations of each for addressing the special characteristics of community-based prevention. In Chapter 5 the committee lays out its vision for the future of valuing community-based prevention.
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