Executive Summary

Health-care professionals, patients, families, community leaders, and policy makers all struggle to understand interactions between health and behavior and to use that knowledge to improve the health status of individuals and populations. Health and behavior are related in myriad ways, yet those interactions are neither simple nor straightforward. Given the wide acknowledgment that cigarette smoking is linked to a variety of deadly diseases, for example, why do people start smoking? And given equally convincing evidence connecting excess weight with cardiovascular disease and other health problems, why are so many people far above their optimal weight? Does such unhealthy behavior indicate a simple lack of willpower? How does the social environment influence these behaviors? Does stress make people sick, or does illness produce stress? This report presents current knowledge about links between health and behavior, about the influence of the social environment on these behaviors, and about interventions to improve health through modifying behavior or personal relationships. It also addresses what must still be learned to answer questions like those above.

The committee entered into its endeavor expecting to discover and share what works and what does not regarding health and behavior. After diligently exploring the literature, the complexity of the issue became evident. The committee noted the vast array of interventions at various levels, with varying endpoints on different populations, with different meth-



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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences Executive Summary Health-care professionals, patients, families, community leaders, and policy makers all struggle to understand interactions between health and behavior and to use that knowledge to improve the health status of individuals and populations. Health and behavior are related in myriad ways, yet those interactions are neither simple nor straightforward. Given the wide acknowledgment that cigarette smoking is linked to a variety of deadly diseases, for example, why do people start smoking? And given equally convincing evidence connecting excess weight with cardiovascular disease and other health problems, why are so many people far above their optimal weight? Does such unhealthy behavior indicate a simple lack of willpower? How does the social environment influence these behaviors? Does stress make people sick, or does illness produce stress? This report presents current knowledge about links between health and behavior, about the influence of the social environment on these behaviors, and about interventions to improve health through modifying behavior or personal relationships. It also addresses what must still be learned to answer questions like those above. The committee entered into its endeavor expecting to discover and share what works and what does not regarding health and behavior. After diligently exploring the literature, the complexity of the issue became evident. The committee noted the vast array of interventions at various levels, with varying endpoints on different populations, with different meth-

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences odologies. Each committee member brought to the table their own perspective about what would be most effective, but the data were inadequate to convince any of the experts of a best approach to shaping and maintaining behavior change. While conventional wisdom tells us that we need to do more exercise, eat less, avoid tobacco, wear seatbelts, and be careful with firearms, deciding what specific interventions to produce and sustain these changes presents a dilemma. A critical obstacle to answering definitively the question of what works best is the difficulty of generalizing the findings of current studies. Many factors contribute to the problem: outcome measures among the studies differ, populations studied differ, and methodologies differ. For example, an intervention may be exceptionally effective on a highly motivated population but fail for the general public. Measurement of a behavioral outcome such as self-reported tobacco use is difficult to compare with an outcome measure such as change in sales of tobacco. Another obstacle is that there are no rigorous evaluations of interventions. Evaluations may assess short-term changes, but long-term effectiveness should also be assessed because maintaining behavior change has been shown to be difficult. Only with additional research and evaluation of interventions will the best approaches be found. This report presents the current level of understanding and demonstrates the limits of the currently available research. In preparing this report, the Committee on Health and Behavior: Research, Practice and Policy examined recent scientific advances about the biological, psychological, and social determinants of health and about the nature of the interactions between health and behavior. It also looked at research addressing interventions intended to change health-related behavior, cognition, and emotions, or interactions with the social environment (i.e., psychosocial factors) with the aim of improving health. Finally, it considered how to translate this knowledge from research to application. The committee approached its charge with a broad vision of a variety of basic and applied sciences. This broad approach facilitated the recognition of relationships among different determinants of health and from various scientific disciplines. The tradeoff is that some subjects were not treated in depth or at all in the report, although wherever possible references are provided for readers who would like more information. The overall findings and recommendations appear at the end of this summary.

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences DEFINITION OF BEHAVIOR As in the 1982 Institute of Medicine report on Health and Behavior, this report uses the term “biobehavioral sciences” to encompass the many disciplines that contribute to behavior and health because it reflects the rich, dynamic, and interactive nature of the fields contributing to knowledge of health and behavior. The term biobehavioral sciences includes not only the behavioral sciences that conduct experimental analyses of animal and human behavior but is broadly inclusive of relevant sciences such as neuroanatomy, neurology, neurochemistry, endocrinology, immunology, psychology, psychiatry, epidemiology, ethnology, sociology, and anthropology, as well as the new interdisciplinary fields such as behavioral genetics, psychoneuroimmunology, and behavioral medicine. DEFINITION OF HEALTH Health is sometimes negatively defined as the absence of disease and injury, sometimes as a normative judgment referring to the average state of most people, and sometimes as a positive concept of well-being. This report uses “health” with the meaning of “positive health.” Although disease is commonly regarded as either present or absent, most health problems fall on a continuum. Changing diagnostic thresholds—such as reducing the body mass index guide for overweight from 28 to 25—can abruptly change the health status for large numbers of people. Furthermore, current wellness or illness must be considered together with prospects for the future. The concept of “positive health,” while controversial, derives from evidence that attitudes and behaviors enhance the body’s resistance to and recovery from disease, illness, and surgical intervention. RISK FACTORS Individuals (and the physiological and psychological processes within them) develop and live in social systems. People influence and are influenced by their families, social networks, the organizations in which they participate, their communities, and their society. Interventions to improve health or to influence health-related behavior can occur at any one or several of those levels. A full understanding of the interactions between health and behavior requires consideration of the separate levels and the interplay among them.

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences Biobehavioral Factors A growing body of evidence shows that the physiological systems associated with the response to stress are potent contributors to illness. The response to stressful challenges helps to maintain constant and appropriate internal conditions, called homeostasis. The stress response involves reactions to emergencies and a rapid and pervasive adjustment of internal states to prepare the organism for fight or flight, but long-term behavioral, physiological, and psychological factors contribute. The cumulative, converging effects of these various factors culminate in patterns shown in the physiological mediators of the stress response including the failure to shut them off when they are not needed. The cost to the body produced by overactive mediators is called allostatic load. Allostasis is the process of adaptation and connotes the maintenance of stability (or homeostasis) through change. Allostasis thus describes a process of adaptation to challenge; allostatic load is the wear and tear on the body as a result of repeated allostatic responses. Allostatic load is more than chronic stress. It can also reflect a genetically or developmentally induced failure to cope efficiently with the normal challenges of daily life. Developmental influences are implicated in influencing individual susceptibility to stress-related disorders. Changes in balance among neurotransmitters in the brain from the time of early development through adulthood to old age can influence behavioral responses to potentially stressful situations, can alter the interpretation of stimuli, and might be associated with anxiety and depression. Research with laboratory animals indicates that early-life experiences strongly influence lifetime allostatic load. For example, in laboratory animals poor maternal care is associated with increased behavioral and stress hormone reactivity in adult life. The immune system is highly integrated with other physiological systems. It is sensitive to virtually every hormone, and sympathetic, parasympathetic, and sensory nerves innervate the organs of the immune system. The nervous, endocrine, and immune systems communicate bidirectionally through common hormones, neuropeptides, and cytokines. Stress-induced activation of neuroendocrine pathways has been shown to modulate various physiological systems, including the immune system. Stress-induced modulation of the immune system has been linked to the expression of inflammatory, infectious, and autoimmune diseases. Several psychological factors—including hostility, anger, depression, and vital exhaustion—have been associated with susceptibility to diseases

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences such as coronary heart disease. Strong links have been identified between the trait of hostility and the incidence of and mortality from heart disease. Some hypothesize that people who are hostile have exaggerated cardiovascular reactivity to stress and that this either contributes to the development of atherosclerosis or triggers acute events. However, hostility also is correlated with increased likelihood of smoking, with decreased likelihood of quitting smoking, and with lower socioeconomic status. Each of these will increase allostatic load. Depression affects about half of patients who experience myocardial infarction, predicts significantly poorer outcome with heart disease, and roughly doubles the risk of recurrent cardiovascular events. Hope and optimism, in contrast, have been suggested as important components of psychological well-being and as factors that can contribute to good physical health. There is increasing evidence that these and other psychosocial factors are important determinants of physical health and disease. People show large differences in resilience to and recovery from illness, injury, or surgery and in how they overcome adversity. Resilience, the ability to recover from adversity, is thought to result from cellular processes that protect and build cells and tissues—processes that involve some reserve capacity and resistance to the damaging effects of stressors— but relatively little is known about its physiological basis and psychosocial influences. Another important construct is coping, the volitional management of stressful events or conditions and regulation of cognitive, behavioral, emotional, and physiological responses to stress. Successful coping is facilitated by a cognitive style characterized by realistic optimism—the tendency to anticipate positive outcomes. Conversely, pessimistic thinking is associated with coping that involves avoidance and social withdrawal, which are related to higher symptoms of anxiety and depression. Behavioral Factors Several behaviors that exert a strong influence on health are reviewed in this report: tobacco use, alcohol abuse, physical activity and diet, sexual practices, and disease screening. Although epidemiologic data on the relationships between these behaviors and various health outcomes were available in the early 1980s, many refinements in knowledge have occurred since then. Causal conclusions have been strengthened by more sophisticated research designs, dose/response relationships have been clari-

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences fied, the influence of many of these behaviors on overall public health has been quantified, and scientific guidelines have been formulated. One example of behavioral influences on health is the impact of diet and physical activity on obesity, a serious risk factor in many diseases such as heart disease and diabetes. Although overweight and obesity are increasing among all sociodemographic groups in the United States, the prevalence is influenced by specific sociocultural variables, including gender, ethnicity, socioeconomic status, and education. Obesity in children and adolescents also is increasing and, because it often persists into adulthood, enhances the risk of chronic disease later in life. Contributing to this epidemic is the fact that relatively few Americans participate in regular physical activity. Furthermore, an increasing proportion of the population is eating outside the home, consuming larger portions of higher calorie and higher fat foods. Preventing weight gain in the first place reduces the likelihood that conditions such as hypertension and diabetes will develop. Because treatment of obesity has poor long-term success, and lost weight often is regained, avoiding weight gain is preferable. Since many dietary habits are established during childhood, educating school-aged children about nutrition has been demonstrated to help establish healthy eating habits early in life. Weight loss in adults is beneficial but difficult to maintain and requires permanent lifestyle changes that combine good dietary habits, decreased sedentary behavior, and increased physical activity. Changes in the physical and social environment can help people maintain the necessary long-term lifestyle changes both for diet and for physical activity. Physical activity does not need to be vigorous to be beneficial to health. For people who are inactive, even small increases have been associated with measurable health benefits. Weight loss accompanied by proper diet can promote health: for example, diets low in saturated fatty acids and cholesterol and higher in polyunsaturated fat are associated with low risks of coronary heart disease. Social Factors Most behaviors are not randomly distributed in the population, but are socially patterned and often occur together. Many people who drink also use tobacco. Those who follow health-promoting dietary practices also tend to be physically active. People who are poor, have low levels of education, or are socially isolated are more likely to engage in a wide array

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences of risk-related behaviors and less likely to engage in health-promoting ones. Understanding why unhealthy behaviors are more prevalent among those with lower social standing requires recognizing that behaviors once thought of as falling exclusively within the realm of individual choice occur in a social context. The social environment influences behavior by shaping norms; enforcing patterns of social control (which can be health promoting or health damaging); providing or not providing environmental opportunities to engage in particular behaviors; and reducing or producing stress, for which engaging in specific behaviors might be an effective short-term coping strategy. Furthermore, environments place constraints on individual choice. Lower mortality, morbidity, and disability among socioeconomically advantaged people have been observed for hundreds of years, using various indicators of socioeconomic status and multiple disease outcomes. A solid body of evidence at the individual level shows that social integration, the quality of social ties, and extent of social support are critical in influencing disease processes and mortality. At the population level, research shows that patterns of social cohesion and social capital are related to health outcomes. Researchers examining social relationships in early and later life describe the importance of deep, meaningful, loving human connections and of affect in intimate relationships. Individuals on positive relationship pathways (positive ties with parents during childhood, intimate ties with spouse during adulthood) are less likely to exhibit high allostatic load than are those on negative relationship pathways. Relational strengths also appear to offer protection against cumulative economic adversity. Strong social relations, however, do not always improve a person’s health status. Evidence documents the adverse consequences of divorce and bereavement, deficits in belongingness, and loneliness. Caregivers of relatives with progressive dementia exhibit impaired wound-healing compared with controls matched for age and family income. Social conflicts have been shown to increase susceptibility to infection. Social isolation and loneliness are associated with physiological changes involving blood pressure, catecholamines, and aspects of cellular and humoral immune function. A social network is the web of social relationships and and the structural characteristics of that web. Prospective cohort studies in the United States, Scandinavia, and Japan consistently show that people who are isolated or disconnected from others are at increased risk of dying prema-

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences turely. Epidemiological evidence consistently supports the notion that social ties, especially intimate ties and emotional support provided by them, promote increased survival and better prognosis among people after myocardial infarction or with serious cardiovascular disease. Generally, social networks are related more strongly to mortality than to the incidence or onset of disease. Perhaps the most striking finding that emerges from the analyses of social environmental influences is the graded and continuous nature of the association between income and mortality, with differences persisting well into the middle-class range of incomes. The fact that socioeconomic differences in health are not confined to segments of the population that are materially deprived in the conventional sense suggests strongly that socioeconomic differences are not simply a function of absolute poverty. Moreover, because causes of death that are purportedly not amenable to medical care show socioeconomic gradients similar to those of potentially treatable causes, differential access to health care programs and services cannot be solely responsible for these differentials in health. Finally, because the gradient in morbidity and mortality persists even between middle class and well-to-do men and women, and even in societies in which material conditions are very good, it seems unlikely that gradients are due solely to material circumstances per se. It has become evident that community socioeconomic status independently influences mortality. Understanding the dynamics of why some populations have particular risk distributions leads to different etiologic questions than does focusing on the reasons some individuals are in the extremes of the risk distribution. Pursuing a population-based strategy, rather than a high-risk strategy, leads to different research questions and policy approaches. HEALTH-RELATED INTERVENTIONS Interventions must recognize that people live in social, political, and economic systems that shape behaviors and access to the resources they need to maintain good health. This report approaches interventions with an ecologic or social-systems perspective that places the person in his or her primary social context and observes how he or she interacts with other important factors to affect and be affected by disease outcomes. The ecologic perspective emphasizes the importance of family, organizations, communities, and society as a whole.

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences Individual Behavior Growing evidence suggests that effective programs oriented toward individual health behaviors require a multifaceted approach to helping people adopt, change, and maintain healthful behavior. Maintaining a particular behavior over time might require different strategies than will establishing that behavior in the first place. Models of behavior change have been developed to guide strategies to promote healthy behaviors and facilitate effective adaptation to and coping with illness. The models are useful constructs for thinking about behavioral change and designing interventions. Each model has its own focus on specific behavioral attributes and its own set of limitations. Given the particular difficulty in maintaining behavior changes, the relapse of behaviors that have been eliminated (or “extinguished”) by an intervention is of particular interest. Research into the classical conditioning model shows that extinction of behaviors does not involve unlearning, but rather new learning that does not overwrite the original behavior. While original learning of a behavior readily extends to new contexts of physical, social, and emotional environments, extinction does not. Those findings suggest that the effectiveness of an intervention to reduce or eliminate a health risk, such as cigarette-smoking, will be limited to the extent that it is bound to the context in which it is delivered. Education and counseling can promote primary prevention measures (e.g., preventing tobacco use, choosing a healthy diet). Interventions aimed at secondary prevention behaviors can influence early detection of illness. For instance, willingness to self-examine and participate in screening procedures is important for detection and treatment of cancer. Counseling by a primary care physician can be effective in changing the behaviors of patients. Effectiveness is improved by the recognition that different patients have different needs. Some patients respond favorably to printed materials and some to coaching via telephone-based counseling, but some cannot change health-related behavior without one-on-one structured education and counseling supplemented by frequent reinforcement from their physicians. Multiple modalities of support are used in the practices that are most heavily committed to encouraging beneficial behavior change and that target individual patients. However, engaging busy practices to reach into new health promotion endeavors rather than to focus on delivery of acute care is challenging. Health-care systems and practices in the United States are moving toward a continuous improvement model of identifying problems and testing interventions, instead of the tradi-

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences tional methods of identifying faulty practices by investigating clinical cases that have unsatisfactory outcomes. Little research funding in the past has been applied to systematic evaluation of fundamental (systemic) changes in clinical practices that might support health-enhancing behavior change in defined populations. Psychosocial interventions can improve people’s coping skills and provide emotional support, thereby improving quality of life and medical outcomes among the chronically ill. Poor adjustment to illness can substantially increase the cost of medical care. Thus, providing appropriate psychotherapeutic and psychopharmacologic treatment for the the chronically ill not only can improve coping and reduce patient discomfort but also can make the delivery of medical care more efficient. For example, there is evidence that psychosocial interventions can improve quality of life, psychological adjustment, health status, and survival of cancer patients. The mechanisms through which psychosocial interventions exert their effect are unknown, but it has been suggested that depression exacerbates symptoms and that psychotherapy augments the immune response. In response to mounting evidence that behaviors, such as tobacco use and consumption of high-fat diets, are risk factors for chronic diseases, several studies target interventions for medically at-risk individuals. Other interventions arise from the concept of population-attributable risk, which measures the amount of disease in the population that can be attributed to a given exposure. A large number of people exposed to a small risk might generate more cases than will a small number exposed to a high risk, so that when risk is widely distributed in the population, small changes in behavior across an entire population can yield larger improvements in population-attributable risk than would larger changes among a smaller number of high-risk individuals. Population-based intervention trials in a community, worksite, or school often focus on changing individual behavior for primary prevention of disease. Several early population-based community intervention studies tracked changes in morbidity and mortality and showed some success. Subsequent intervention studies, however, had insufficient funding to follow participants for long enough or in sufficient numbers to determine long-term costs and consequences of the interventions for survival. Instead of quality of life, or disease incidence, these programs used behavior change as the primary outcome because evidence strongly linked behavior to morbidity and mortality. In addition, the smaller community-wide studies were less likely to achieve the necessary intensity and breadth

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences to show significant intervention effects. Workplace interventions for individual behavior change have been increasing in the past 15 years. The interventions range from intensive group behavioral counseling sessions and supervised exercise prescriptions to simple, broad approaches such as mailed self-help materials and newsletters. Although several of the programs achieved statistically significant effects, the quality of the studies was generally inadequate to make judgments about the effectiveness of the interventions. Schools also provide a setting for behavior-change interventions. Interventions at this level have met with varied success. Recognition of multilevel influences on smoking in youths, for example, has led to multifaceted interventions, including schoolwide media campaigns in combination with individual approaches. Reviews of youth smoking-control interventions generally conclude that social influence interventions can curb smoking onset, although with a somewhat guarded picture of their efficacy. School-based interventions for physical activity in the 1980s and 1990s were found to improve student knowledge and psychosocial factors but were less likely to change behavior significantly. The more extensive multicomponent interventions typically had better results. Some programs were able to show a sustained difference in physical activity between experimental and control schools for several years. Families Another level of intervention for health-related behavior change focuses on the family. Family relationships have greater emotional intensity than do most other social relationships, and evidence suggests a substantive, positive association between the specific bonds within families and chronic-disease management and outcomes. Chronic disease is a long-term stressor for patients and their families. Significant changes are required of the patient and family members in day-to-day activities and in the way they relate to one another. Parents, spouses, and other family members are frequently the patient’s primary source of support, and their ability to meet the patient’s needs is often compounded by the distress that illness generates among other family members. In addition, family members frequently provide important channels of community resources to patients. Family relationships also determine the capacity for regulation of emotional and psychological processes. Stable, secure, and mutual family relationships enhance disease management behavior by permitting a sharing

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences of the burdens associated with disease. Family members often determine important contextual factors that affect health-related behavior, such as diet and exercise. Most family-based, clinical-intervention research has concerned chronic diseases of childhood and adolescence (e.g., insulin-dependent diabetes, asthma). Interventions have focused more on adherence to treatment and metabolic control than on family-behavior variables or family processes themselves. However, a few studies demonstrate improved family relationships associated with better health outcomes. Family-focused intervention studies of dementia in the elderly (especially Alzheimer’s disease) are increasing, but relatively less attention has been directed to family-focused interventions for diseases of adulthood. The available data suggest that recognizing and attending to the family relationship context adds considerably to improving the health and well-being of patients and family members struggling with the management of a chronic disease. Organizations Formal and informal organizations constitute another framework for describing interactions between behavior and health. Organizations are important components of social and physical environments, and they exert considerable influence over the choices people make, the resources they have to aid them in those choices, and the factors in the workplace that could influence health status (e.g., work overload, exposure to toxic chemicals). As employees, consumers, customers, clients, and patients, people are influenced by the organizations to which they belong. Well-evaluated interventions at the organizational level are scarce. Some worksite health promotion programs include employee participation in planning the efforts ranging from soliciting employee input through surveys or focus groups to having employee groups take full responsibility for implementation. Evaluation of these interventions is limited, and results have been mixed. Another strategy relies on training key figures in the organizations in methods for creating a supportive organizational culture and developing a comprehensive health promotion program. Again, the interventions and assessments are limited. One important aspect of organizational interventions is the occupational safety and health (OSH) programs that address the influence of physical (e.g., noise, extreme temperatures), chemical, ergonomic, and psychosocial work hazards on employee health. Strategies to enhance compliance with universal precau-

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences tions among health-care workers provide a case in point: although descriptive research clearly indicates the influence of organizational safety climate and work task design on compliance rates, most interventions have targeted only individual employee knowledge, attitudes, and behaviors for change. Organizations have also intervened to reduce on-the-job psychosocial stressors. Programs that focused solely on individual-level coping enhancement—even when they involved substantial resources— were less effective than programs that attempt to change work organization, task structure, or communication patterns in worksites. Communities Communities also provide an important level of intervention for improvement of health. A community need not be a geographic area, but instead might be a unit of identity. A community of identity can exist within a defined geographic neighborhood or, for example, as a graphically dispersed ethnic or professional group in which there is a shared sense of identity. Communities are also “units of solution” that include members with the knowledge, skills, and expertise necessary to solve problems. Community-level interventions can reduce the social, structural, and environmental stressors that degrade health status and that are beyond the ability of any single person to control or change. Community-level interventions also can strengthen the situational factors, such as social support, community empowerment, community capacity, and social cohesion, that have been shown to protect against deleterious effects of stress. Community interventions present a complex set of challenges. In general, they emphasize the social, cultural, economic, and political context of communities of identity and involve the community in the control and development of the process for which full specification of goals and objectives is not possible at the beginning. The very nature of these interventions and the necessary commitment to the long time-frame required to bring about major community-level changes preclude application of traditional evaluation designs and methods to assess effectiveness. Lessons from experiences with community interventions include the importance of the community, rather than an outside organizer, in defining needs and priorities;

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences the need for an initial and continuing community diagnosis and assessment to identify and build on community strengths and resources; the flexible implementation of theories and methodologies, tailoring them to a particular community context; the importance of using participatory and empowering approaches to evaluate community- level change interventions; the necessity of long-range planning and developing diversified bases of funding. Emphasis is needed on public health interventions that involve communities of identity with the goal of collectively identifying resources, needs, and solutions that can influence community-level variables. Society There is an inverse relationship between social class and a variety of diseases. Even beyond the stressors associated with low income, social structure clearly shapes people’s daily lives. There are many ways in which the effects of income extend beyond purchasing power. People in middle-class neighborhoods have proportionally more pharmacies, restaurants, banks, and specialty stores; low-income areas have more fast-food restaurants, check-cashing stores, liquor stores, and laundromats. Many social, economic, political, and cultural factors are associated with health and disease for which changes in individual health behaviors alone are not likely to result in improved health and quality of life. Public health laws provide a number of approaches to prevent injury and disease and to promote the population’s health. First, government interventions can be aimed at individual behavior—through education, deterrence, or incentives. Health communications campaigns are designed to educate and persuade people to make healthier choices. The government can deter risk behaviors by imposing civil and criminal penalties (e.g., seatbelt and motorcycle helmet laws) or by creating incentives for individual behavior change (e.g., imposing taxes on tobacco or alcohol). Second, the government can require safer product design (e.g., passive restraints in cars, trigger locks on handguns, or childproof caps on medicines). Finally, the law can change the informational, physical, social, or economic environment to facilitate safer behavior. Such approaches can include accurate labeling and instructions (e.g., on foods, pharmaceutical products, or nutritional supplements); restrictions on commercial advertising of haz-

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences ardous products and activities (e.g., tobacco, alcoholic beverages, gambling); and creation of housing and building codes to prevent injury and disease (e.g., sanitation, lead paint) and to make environments safer (e.g., guards on upper-level apartment windows, median barriers on highways, regulations for safe disposal of toxic substances). AN INTERVENTION CASE STUDY: TOBACCO Tobacco control provides a good illustration of the translation of research to application. This example was selected because there is substantial evidence that tobacco use causes ill health, public health interventions and clinical effectiveness have been evaluated, and cost-effectiveness studies are available. Many approaches have been used to decrease the prevalence of tobacco use. Despite the multitude of interventions, it is still not possible to conclude what works and what does not. Some general conclusions can be drawn. At the individual level, there have been reviews of thousands of studies on clinical interventions to reduce tobacco use. The findings suggest that counseling and pharmacotherapies are effective. Community-based interventions have shown variable success. Many of them have been directed toward youth in the belief that they would have the greatest impact for the future. Some very well designed intervention trials, however, conclude that the approaches used were ineffective. A review of government-level approaches to tobacco use prevention and cessation revealed that single approaches via clean air laws, price increases, counter-advertising, enforcement of existing laws restricting youth access, and others may be effective with some people. However, a combination of these approaches has the greatest possibility of success. In summary, there is limited evidence that any single step is effective in reducing tobacco use. Although a number of studies have been published, many if not most suffer from design flaws that fail adequately to consider co-factors existing in the community. The conclusion of the committee is that a multi-pronged approach including (but not limited to) education, clinical intervention, price increases, restricted access to tobacco, clean air laws, and counter-advertising must be used. In current tobacco users, counseling and pharmacotherapies have the greatest potential.

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences FINDINGS AND RECOMMENDATIONS Finding 1: Health and disease are determined by dynamic interactions among biological, psychological, behavioral, and social factors. These interactions occur over time and throughout development. Cooperation and interaction of multiple disciplines are necessary for understanding and influencing health and behavior. Recommendation 1: Funding agencies should direct resources toward interdisciplinary efforts for research and intervention studies that integrate biological, psychological, behavioral, and social variables. The investigations that will be most productive will reflect an understanding of the complexity and interconnections of disciplines. Collaborations across disciplines need to be encouraged and expanded. Finding 2: A fundamental finding of the report is the importance of the interaction of psychosocial and biological processes in health and disease. Psychosocial factors influence health directly through biological mechanisms and indirectly through an array of behaviors. Social and psychological factors include socioeconomic status, social inequalities, social networks and support, work conditions, depression, anger, and hostility. Recommendation 2: Research efforts to elucidate the mechanisms by which social and psychological factors influence health should be encouraged. Intervention studies are needed to evaluate the effectiveness of modifying these factors to improve health and prevent disease. Such intervention studies should span the breadth of all phases of clinical trials, from feasibility studies to randomized double-blind studies. Community-based participatory research should also be conducted. Research should include all levels of intervention, from individual to family, community, and society. Finding 3: Behavior can be changed: behavioral interventions can successfully teach new behaviors and attenuate risky behaviors. Maintaining behavior change over time, however, is a greater challenge. Short-term changes in behavior are encouraging, but improved health outcomes will often require prolonged interventions and lengthy follow-up protocols. Recommendation 3: Funding for health-related behavioral and psychosocial interventions should support realistically long-duration efforts.

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences Finding 4: Individual behavior, family interactions, community and workplace relationships and resources, and public policy all contribute to health and influence behavior change. Existing research suggests that interventions at multiple levels (individual, family, community, society) are most likely to sustain behavioral change. Recommendation 4: Concurrent interventions at multiple levels (individual, family, community, and society) should be encouraged to pro mote healthy behaviors. Assessments of coordinated efforts across levels are needed. Such efforts should address the psychosocial factors associated with health status (e.g., access to healthy foods or safe places to exercise) as well as individual behavior. Finding 5: Initiating and maintaining a behavior change is difficult. Evidence indicates that it is easier to generalize a newly learned behavior than to change existing behavior. The old adage “an ounce of prevention is worth a pound of cure” is valid in the context of behavior and health as well. Recommendation 5: Resources should be allocated to the promotion of health-enhancing behavior and primary prevention of disease. This should be a priority for public health and health care systems. Finding 6: The goals of public health and health care are to increase life expectancy and improve health-related quality of life. Many behavioral intervention trials document the capacity of interventions to modify risk factors, but relatively few measured mortality and morbidity. However, ramifications of interventions are not always apparent until they are fully evaluated, and unexpected consequences can result. Recommendation 6: Intervention research must include appropriate measures (including biological measures) to determine whether the strategy has the desired health effects. Finding 7: Changing unhealthy behavior is not simply a matter of “willpower.” Individual behavior has biological underpinnings and consequences and is influenced by the social and psychological contexts in which it occurs. While biological interventions and exhortations to individuals to change their behaviors are easier to administer, changes in social factors, policies, and norms are necessary for improvement and maintenance of population health. Much can be learned as states change cigarette taxes, create controls on public advertising for various products,

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Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences and increase or decrease opportunities for exercise during the school day or as communities implement or eliminate walking and bicycle paths. Such social and policy decisions are rich opportunities for learning about behavior change and health. Recommendation 7: Program planners and policy makers need to consider modifying social and societal conditions to enable healthy behavior and social relationships. Interventions must be evaluated to enable continuous improvement of programs and policies. Research in these domains should be rigorous and scientific, but method should not dominate substance. Longitudinal research designs, natural experiments, quasi-experimental methods, community-based participatory research, and development of new research methods are necessary to advance knowledge in these areas.