This report reflects the increasing attention being paid to the behavioral and psychosocial factors that enhance or compromise health. Many behaviors—tobacco use, excessive alcohol consumption and abuse of other substances, unhealthy diet, sedentary lifestyle, and nonadherence to medication regimens—are recognized as health-compromising. Evidence for the effects of social stressors, socioeconomic status, social support, and social capital on health outcomes is growing. First, this chapter explores the interactions of risk factors. Next, it presents the example of tobacco interventions to illustrate an effective multilevel approach and the difficulties in evaluating the interventions. Finally, it presents recommendations for research and practice regarding health and behavior.
INTERACTIONS AMONG RISK FACTORS
Recent decades have seen increasing attention given to the contribution of psychosocial factors, particularly behavior, to promoting or compromising health. The relationship between some behaviors and health status has been recognized since the 1974 Lalonde report. Healthy People (U.S. Department of Health, Education, and Welfare, 1979) and Health and Behavior: Frontiers of Research in the Biobehavioral Sciences (IOM, 1982) documented the importance of behavior to the burden of illness and disabilities in the United States.
The association of tobacco use with heart disease, a variety of cancers, and poor pregnancy outcomes is perhaps the best known and most dramatic example of the interactions addressed in this report. However, the association of physical activity with fitness and health, dietary nutrients with health or illness, and excessive alcohol consumption with driving fatalities and poor pregnancy outcomes also are recognized widely.
Recently, basic and applied research from a range of disciplines has demonstrated the importance of reciprocal interactions over time among health and biological, psychological, and social factors. Biological factors include genes, neurochemical and hormonal processes, and the functioning of physiological systems. Psychological factors include behavioral, personality, temperamental, cognitive, and emotional variables. Social factors include socioeconomic status, social inequalities, social networks and support, and work conditions. It is now evident that the relationships between health and many behaviors are much more complex than previously thought. Evidence attests that psychosocial factors influence health directly through biological mechanisms and indirectly through an array of behaviors.
Example: Social Status and Health
The role of social status in health and behavior is an example of interactions among biological, psychological, and social factors and health. Lower mortality, morbidity, and disability rates among socioeconomically advantaged people have been observed for hundreds of years, and studies have documented these effects using various indicators of socioeconomic status (SES) and multiple disease outcomes (Kaplan and Keil, 1993). Perhaps the most striking finding is the graded and continuous nature of the association between income and mortality, with differences persisting well into the middle-class range of incomes (Chapter 4). The fact that socioeconomic differences in health are not confined to segments of the population that are materially deprived in the conventional sense argues against an interpretation of socioeconomic differences as simply a function of absolute poverty. Moreover, because causes of death that seem not amenable to medical care show socioeconomic gradients similar to those of potentially treatable causes (Davey Smith et al., 1996; Mackenbach et al., 1989), differential access to health-care programs and services cannot entirely explain socioeconomic differences in health (Wilkinson, 1996).
People who are poor, have low levels of education, or are socially isolated are more likely to engage in risk-related behaviors and less likely to engage in health-promoting behaviors (Adler et al., 1994; Matthews et al., 1989). Behaviors (Chapter 3) occur in specific social contexts. Social environments influence behavior by shaping norms (e.g., the extent to which tobacco use is discouraged or encouraged); enforcing patterns of social control; providing or not providing opportunities to engage in particular behaviors (e.g., safe places to exercise, availability of nutritious foods); and reducing or producing stress, for which engaging in specific behaviors might be an effective coping strategy, at least in the short term (Berkman and Kawachi, 2000).
The stresses associated with environmental and behavioral factors contribute to illness (Cohen and Herbert, 1996; Cohen et al., 1991; Hermann et al., 1995; Kiecolt-Glaser et al., 1996; McEwen, 1998). “Allostatic load” refers to the wear and tear that the body experiences as a result of the repeated activation of the stress response; it also includes contributions of food, alcohol, tobacco, exercise, and sleep through their ability to influence the production of stress hormones (McEwen, 1998; McEwen and Stellar, 1993). The “stress response” triggers and modulates physiological effects that can promote disease including modulation of the immune system (Chapter 2).
Producing Behavior Change
Behavior can be changed and those changes can influence health. Interventions can successfully teach health-promoting behaviors or attenuate risky behaviors. Interventions aimed at management of chronic pain, smoking cessation, coping with cancer, and amelioration of eating disorders have been demonstrated empirically to be effective (Compas et al., 1998). Studies show that family or structured-group support, patient education, and behavior-based interventions can increase adherence to prescribed medication regimens (Anderson, 1996). Education aimed at increasing knowledge, control, and confidence (self-efficacy) among diabetics has produced benefits in both attitude and blood glucose management (Anderson et al., 1995). Many studies show that psychological interventions, especially those involving cognitive behavioral methods to enhance coping, are effective in facilitating adaptation to and coping with rheumatoid arthritis (Keefe and Caldwell, 1997; Lorig and Holman, 1993;NIH Technology Assessment Panel, 1996; Parker, 1995).
Studies of support groups, provision of education and information, expression of emotions, and hypnosis suggest the utility of these approaches in the treatment of a range of conditions, including irritable bowel syndrome (Whorwell et al., 1984, 1987), peptic ulcer disease (Klein and Spiegel, 1989), coronary heart disease (Linden et al., 1996), and cancer (improving quality of life and psychological adjustment of cancer patients, possibly affecting health status and survival; see reviews by Andersen, 1992; Compas et al., 1998; Fawzy et al., 1995; Helegeson and Cohen, 1996; Meyer and Mark, 1995). Interventions for insulin-dependent diabetes patients that involved family members meeting together with patients showed an effect on metabolic control (Delamater et al., 1990; Ryden et al., 1994; Satin et al., 1989), but interventions with patients and family members separately did not (McNabb et al., 1994; Thomas-Dobersen et al., 1993). Further research is needed to replicate the results of those studies, determine their efficacy, and identify the conditions under which specific types of psychosocial interventions are most effective.
Maintaining Behavior Change
Maintaining induced behavior change over time and across a variety of settings remains a problem, however, for behaviors as diverse as smoking (Ockene et al., 2000), physical activity (Marcus et al., 2000), diet and weight loss (Jeffery et al., 2000), and adherence to medication regimens. Although interventions can effectively lead to weight loss or smoking cessation, for example, substantial proportions of those who are successful will regain the lost weight or resume smoking. Most studies, though demonstrating the ability to alter behavior, either do not test, or when tested do not demonstrate, sustained behavior change. These factors present major challenges for the research and application of behavioral interventions and point to the need for long-term studies.
Individual behavior has biological underpinnings and consequences and is influenced by the social and psychological contexts in which it occurs. Therefore, changing behavior is generally not simply a matter of personal choice. Instead, interventions are likely to be most effective when they address the individual and the psychological and social contexts in which the behavior occurs. This suggests the utility of intervening at the multiple levels that influence behavior individual (physiological, psychological), family, social networks, organizations, community, and society (state or national population). For example, a person might lose weight as the result of an intervention, but in the months and years after that intervention, the effects of family and friends, eating and offering favorite fatty foods, advertisements for high-calorie treats, exposure to situations in which more nutritious food is not readily available, stress at work combined with little time to seek out nutritious foods, and confusing labeling or messages emphasizing low-fat but not sugar and caloric content are likely to result in weight gain. Interventions that involve family and community members and others with whom an individual has social relationships; community, organizational, and workplace changes; and public policy interventions have all been demonstrated to affect behavior. However, additional research is needed on the functioning and effectiveness of interventions at the levels of family, community, organizations, and public policy, as well as on combinations of them to determine which might be most effective and under what circumstances. Interventions that focus solely on individual attributes, such as self-control or willpower, to change behavior leave many relevant factors to chance and thus are unlikely to be successful over the long term unless other factors (e.g., family and social relationships, work policies, social norms, and individual stress reactivity) happen to be aligned in a way that is conducive to the desired change.
AN INTERVENTION CASE STUDY: TOBACCO
Tobacco use is the leading cause of preventable death in the United States (McGinnis and Foege, 1993), and 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 (Chapter 3), public health interventions and clinical effectiveness have been evaluated, and cost-effectiveness studies are available.
In 1994, the Agency for Health Care Policy and Research (AHCPR) launched a comprehensive effort to translate research findings on the most effective smoking-cessation strategies into clinical guidelines for health care providers, administrators, and smoking-cessation specialists. AHCPR convened a panel of researchers to summarize the findings of 300 studies into a series of guidelines for clinical practice (USDHHS, 1996; AHCPR, 1996). Primary, secondary, and tertiary prevention strategies were proposed on the basis of meta-analyses of relevant studies:
- A combination of psychosocial counseling and nicotine replacement therapy appeared to be the most effective strategy.
- A dose/response relationship demonstrated that longer counseling sessions (more than 10 minutes) were more effective than were shorter ones (less than 3 minutes) and that more sessions (more than 8) produced better results than did fewer (under 4), but that even fewer or shorter sessions still had a more substantial influence on smoking behavior than did no sessions at all.
- All health-care providers could provide effective counseling that resulted in measurable smoking cessation, but cessation specialists were more effective than were generalists, and multiple providers were more effective than were single providers.
Since that review, new treatments have become available, including nicotine inhalers and nasal spray and bupropion hydrochloride (Hughes et al., 1999). Moreover, the nicotine patch and gum have been made available over the counter. A review of studies of these treatments led to the recommendation that physicians intervene by discussing smoking and potential treatment with every patient who smokes (Hughes et al., 1999). Assessing patients for a combination of behavioral and pharmacotherapeutic approaches also was advised.
The trend in smoking-cessation research has been away from brief interventions studied sequentially to multicomponent interventions that integrate several approaches (Schwartz, 1992). Those programs target smoking at the social, physiological, and psychological levels. They have been found to be more effective in promoting sustained smoking cessation than are single-component approaches (Shiftman, 1993). Recent evidence also suggests that smoking-cessation efforts are more successful when they are tailored to the target population. Specifically, an intervention tailored to specific needs, barriers, and smoking patterns of African Americans resulted in a higher cessation rate at 1 year than did a standard intervention (Orleans et al., 1998).
Opportunities to increase the influence of smoking-cessation strategies are becoming available through managed-care programs in which more aggressive efforts can be undertaken to reach target populations. For example, interactive telephone contact combined with tailored self-help materials (computer-generated recommendations based on questionnaire response patterns; Velicer et al., 1999) and smoking-cessation programs tailored to be responsive to the weight control concerns of women (Suchanek et al., 1999) were provided to substantial portions of the eligible populations and yielded impressive results. Although long-term abstinence rates were low (for instance, around 5–10%), participation of 50–85% produced success rates well beyond what would be expected from a typical reactive program. It should be noted that when success rates were matched to readiness stage (Prochaska, 1997), abstinence significantly improved for those in the preparation stage (to 20–30%) (Velicer et al., 1999), although this stage accounted for only 20% of the sample.
A study by Cromwell et al. (1997) evaluated the cost-effectiveness of 15 smoking-cessation interventions endorsed by AHCPR (1996). The entry in Table 7–4 for smoking cessation comes from that study and shows the result for the guidelines as a whole and for each intervention. The authors presented results in terms of cost per quitter, per life-year saved, and per QALY. They also presented sensitivity analyses that included the time that smokers spent in the programs as a cost. (The committee endorses the inclusion of time, a scarce resource, in costs. Recognizing that analysts do not have much experience with this variable, sensitivity analyses might be the way to start.)
The results of the study by Cromwell et al, (1997) show that smoking-cessation programs are a cost-effective way to improve health. More intensive interventions, which involve more counseling or use of nicotine replacement, are more cost-effective (their higher costs are more than offset by greater effectiveness). The total first-year cost of implementing the guidelines was estimated at $6.7 billion (1997 dollars). The return for that investment would be smoking cessation by 1.7 million people at a cost (in 1997 dollars) of about $4,000 per person. In terms of health outcome, the cost would be $2,800 per life-year, or just over $2,000 per QALY.
Evaluating Clinical Interventions
Chambless and Hollon (1998) have proposed a four-component model for the evaluation of health behavior change strategies: efficacy, effectiveness, generalizability, and cost-effectiveness. In a recent review of smoking-cessation interventions using the Chambless and Hollon model, Compas et al. (1998) identified the most efficacious and effective smoking-cessation programs as multicomponent (typically, cognitive/behavioral therapy combined with nicotine patch or gum or such other pharmacologic agents as buproprion [Hurt et al., 1997], nicotine inhalers, social support, and environmental restructuring) and group-based, consisting of 8–12 sessions (Hall et al., 1994; Hill et al., 1993; Stevens and Hollis, 1989), achieving 1-year abstinence rates of 32–34%. Maintenance sessions that included relapse prevention skill training were particularly effective, raising 1-year abstinence rates to 41%. Other studies (e.g., Cinciripini et al., 1995, 1994) have achieved similar 1-year abstinence rates (44%) with the addition of scheduled smoking-reduction strategies. These rates compare favorably with those of earlier studies (e.g., Hunt et al., 1971) in which 20–25% abstinence after 1 year was the norm.
Chapters 5 and 6 review a number of community, workplace, and school-based interventions targeting the reduction of tobacco use. In the workplace, several programs were successful in reducing smoking among employees through implementation of restrictive tobacco control policies. School-based programs tried to provide educational messages about the health risks of tobacco use and to develop social skills that would allow youths to resist the pressures to smoke. These programs met with varied success, and changes were difficult to sustain.
The study of Altman et al. (1999) illustrates a broad-based community participation approach to reducing tobacco availability and use among adolescents and youths. In that study, four rural communities in Monterey, California, were randomly assigned to treatment or comparison groups. Middle school and high school students in the communities completed questionnaires that evaluated their knowledge, attitudes, and behaviors concerning tobacco use. In the intervention communities, a series of actions were implemented over a 3-year period: widespread community education, training of merchants who sold tobacco, and voluntary policy change. Within the treatment communities, the proportion of stores that sold tobacco to minors dropped from 75% at the baseline assessment to zero at the final evaluation period. There also were reductions in tobacco sales in the comparison communities, but they were much less dramatic (from 64% down to 39%). Although tobacco availability was reduced in the intervention communities, young people still reported that they were able to obtain tobacco from other sources. The strongest effect of the intervention was for younger students (seventh graders). The intervention had only small effects for ninth and eleventh graders.
A recent school-based smoking prevention program (Peterson et al., 2000) calls into question the effectiveness of the social-influences approach to smoking prevention. The Hutchinson Smoking Prevention Project (HSPP), conducted 1984–1999, randomly assigned 40 school districts to experimental or control groups. Students were followed from grade 3 until 2 years after high school. An enhanced social-influence approach to the intervention was used, containing the 15 “essential elements” for school-based tobacco prevention developed by an NCI Advisory Panel (explained in Flay, 1985; Glynn, 1989). Included in the interventions were the following activities. Every year, from grade 3 to grade 10, the students received multiple lessons from trained teachers regarding the strategies for identifying and resisting the influences to smoke, motivating the students not to smoke, and promoting self-confidence in the ability to refuse to smoke. This was supplemented by a biannual newsletter and the availability of materials to help stop smoking. No significant differences between the control and experimental groups were evident at grade 12 or 2 years after high school, suggesting that the intervention had little, if any, impact. The highly controlled, and well-designed nature of the study, including the high follow-up rates, high compliance with the intervention, the maintenance of the randomization by the school districts, well-matched control and treatment groups, and appropriate statistical analysis, strongly suggest that the failure to achieve change was a result of a failed intervention and not poor methodology. This conclusion implies that future interventions need to take a different approach, critically rethinking the interactions of biological, behavioral, and psychosocial risk factors at social and cultural contexts.
Government Level Anti-Tobacco Interventions
The government has adopted multiple strategies to reduce smoking, particularly among children and adolescents. Those interventions are directed toward individual-level behavioral changes using education (e.g., anti-tobacco campaigns), deterrence (e.g., bans on retail sales to minors), and disincentives (e.g., tobacco taxes). They also are directed toward manufacturers (various litigation strategies), information sources (e.g., advertising restrictions), and physical environments (e.g., bans on smoking in the workplace and other public areas). There has been no systematic evaluation of all of the interventions, but researchers have sought to analyze several of the government's anti-tobacco strategies.
It has been half a century since the publication of the first evidence that smoking causes lung cancer (Doll and Hill, 1950). Since 1950, knowledge of the health effects of tobacco use has continued to grow systematically. The increasing number of magazine articles on the risks of cancer parallels the increasing knowledge that tobacco use is harmful (Albright et al., 1988) and suggests a positive association between mass-media coverage and public attitudes concerning smoking (Pierce and Gilpin, 1995; Figure 8.1). Although the increase in public knowledge parallels the incidence of smoking cessation in adults (35–50 years old), even in 1990, the cessation rate in the general population was only around 4%. The data on younger adults (20–34 years old) follow a similar but weaker pattern, with a cessation-rate of about 5% in 1990 (Evans et al., 1995; Gilpin and Pierce, 1997).
The use of the mass-media for anti-smoking campaigns was developed to counter the influence of tobacco industry advertisements promoting smoking. The impact of the media on smoking behavior was most dramatic during the time of the Fairness Doctrine mass-media campaign. In 1967, television networks were required to give equal time to anti-tobacco messages (Pierce and Gilpin, 1995), and per capita cigarette consumption decreased for the first time. In 1972, the tobacco industry voluntarily accepted restrictions on broadcast advertising. Clearly, the use of mass-media can be effective for antitobacco communication.
A major issue of research, policy, and legal debate has been the extent to which tobacco industry communication strategies (cigarette advertising and promotion) encourage teenagers to start smoking (Albright et al., 1988; Gilpin et al., 1997). The tobacco industry's annual budget for advertising and promotional expenditures is upwards of $5 billion. However, a shift is apparent from advertising toward promotional expenditures. In 1995, the tobacco industry reduced its advertising budget and put money into increased incentives to merchants, coupons, and specialty items with visible cigarette brand names or symbols (Emery et al., 1999). Changes in smoking initiation among adolescents can be shown to track with promotional strategies (Pierce et al., 1998a). Joe Camel was introduced in 1985, when smoking initiation by adolescents was at an all-time low (10%), and initiation rates began to rise. With the addition of promotional items like Camel Cash and the Marlboro Miles campaign, and decreases in price, adolescent initiation reached a high of 14% (Evans et al., 1995). Initiation of daily use among minors follows a similar trend. Pierce et al, (1998a) showed that having a favorite brand and being willing to use a promotional item substantially increased the odds that people would move along the smoking-uptake continuum from nonsusceptible never-smoker in 1993 to susceptible or higher in 1996.
Effective antitobacco campaigns have been conducted in Sydney and Melbourne, Australia, and in California (Pierce, 1999). A statewide media-led tobacco control program initiated in Sydney and extended to Melbourne led to a drop in smoking prevalence in both places. The expected delay in effect was observed: Melbourne showed changes after Sydney at the point when the campaign started. The effect was much stronger in males than in females. In California, per capita consumption trends were tracked before, during, and after an antismoking campaign, and smoking behavior was compared with that in the rest of the United States. California showed decreases in per capita consumption and lower consumption overall than the rest of the country. The United States, however, showed a decrease of similar magnitude to that observed in California; no interaction was apparent (Pierce et al., 1998b,c) (Figure 8.2). It is unclear what influence the program had. Similar relationships were observed in measures of smoking prevalence.
Cigarette excise taxes are an attractive public policy tool for two reasons. First, they generate substantial revenue, whether for a local municipality, a state, or the federal government. Second, there is substantial evidence that, by raising the price of a pack of cigarettes, an excise tax increase will reduce cigarette consumption—some smokers will stop and some will cut down (Chaloupka and Grossman, 1996; Hu et al., 1995; Keeler et al., 1993; Lewit et al., 1981; Manning et al., 1991). These behavioral changes eventually might be reflected in improved population health status (Warner, 1986). But the long-term effectiveness of this intervention has yet to be demonstrated.
Elasticity is the term economists use to measure responsiveness to price changes. It is a unitless measure calculated as the percentage change in overall demand that results from a 1 % change in the price of an item. For example, an elasticity estimate of minus 0.40 means that consumption will decrease by 4% in response to a 10% price increase. If fewer people smoke, health benefits are likely. The health benefits, which can be expressed in terms of improved life expectancy and quality of life, are summarized in QALYs. Simulation studies estimate that for a $0.50 tax and an elasticity of minus 0.40, about 25,000 QALYs would result each year. Higher taxes would produce even greater health benefits. The simulations also suggest that the tax has a greater influence each year it is in effect, until a plateau at about 70 years in the future. The reason for the delayed benefit is that youth might be more price sensitive than are older habitual smokers. Thus, the tax could have a greater effect in later years by preventing youths from entering the smoking pool and by inducing current smokers to quit. The analysis suggests that a tobacco excise tax could be among the few policy options that will enhance population health status while raising revenues (Kaplan et al., 2001).
The most encompassing studies have evaluated broad, multidimensional anti-tobacco campaigns initiated in several states. The initiatives differ from one state to another, but they all involve taxation of cigarettes and the use of those revenues for a multipronged approach to reducing smoking. In California, for example, the state mandated funding for health education campaigns, and local health agencies were required to provide technical support and monitor adherence to antismoking laws, community-based interventions, and enhancement of school-based prevention programs (Bal et al., 1990). Evaluation studies in Massachusetts (Abt, 1997), California (Pierce et al., 1998b), and Oregon (Centers for Disease Control and Prevention, 1999) all reported per capita reductions in cigarette consumption.
Despite the promising results shown in the studies, they do have empirical and methodologic limitations. The California study reported a sharp decline in smoking directly after the intervention, but the effect dissipated over time and, ultimately, failed to significantly affect tobacco use (Pierce et al., 1998b). There are several possible explanations. One is that the political and social environment had as much effect as the interventions themselves. Changes in the law, which often are associated with political debate and media coverage, have a “declarative effect” that influences behavior indirectly by changing attitudes. Legal norms reinforce, stimulate, accelerate, or symbolize changes in public attitudes about socially desirable behaviors (Bonnie, 1986). Other possible explanations are temporary reductions in state funding for anti-tobacco programs, political interference with anti-tobacco messages, and industry advertising and pricing policies.
The studies also face challenges in methodology. Most important, public or private funding for evaluation research, including population surveys of smoking behavior, becomes available only after the intervention has occurred. After-the-fact research funding thwarts a comparison of specific behaviors before and after intervention. Even if this important problem could be overcome, however, it would be hard to identify precisely which intervention is having the desired effect. The Massachusetts, California, and Oregon studies, by definition, examined multiple interventions but had no ability to separate the effects of each.
There are, of course, numerous studies of discrete tobacco regulation strategies. Two major interventions that have been studied are programs to prevent youth access to cigarettes and bans on smoking in the work-place and other public places. In the absence of enforcement, banning cigarette sales to minors does not significantly reduce teenage tobacco use. Compliance with the law by retailers is low; youth access studies have demonstrated that most retailers do sell to children. The Tobacco Institute's own “It's the Law” campaign, perhaps predictably, has not been effective (DiFranza and Brown, 1992). Education efforts aimed at retailers have shown an effect, but a small one (Wildey et al., 1995). The most successful legal strategy to reduce youth access imposes civil penalties against store owners (not just clerks), incorporates progressively higher fines culminating in suspension or revocation of the tobacco retailer's license, and forces regular enforcement by using minors in unannounced purchase attempts to monitor compliance. This strategy, implemented by legislation in Woodbridge, Illinois, is successful over time (Jason et al., 1999). Locking devices on cigarette vending machines do not appear to be as effective as outright bans on these machines (Forster et al., 1992).
Legal restrictions on smoking in the workplace and in other public places have demonstrated high conformance with the rule and some reduction in cigarette use. A study of compliance with an indoor clean air act in Brookline, Massachusetts, showed that the law was popular and the incidence of restricted smoking was high (Rigotti et al., 1992). A summary of 19 studies that evaluated the effects of smoke-free workplaces on smoking habits showed that both smoking rates (cigarettes smoked during a 24 hour period) and smoking prevalence (proportion of workers who smoke) decreased as a result of the indoor smoking bans. The authors estimate an annual reduction of 9.7 billion cigarettes (2%) in the United States as a result of smoke-free workplaces (Chapman et al., 1999).
What is notably absent from the evaluative research are rigorous studies of the effects of tobacco litigation and other forms of litigation. Although tort strategies are much used and publicized—by private parties, classes, and state and federal government—there is considerable debate about the effects. Public health advocates strongly favor the approach, whereas some law and economic scholars are skeptical about the tort system as a useful and cost-effective means of intervention (Rose-Ackerman, 1991; Vicusi, 1992).
The experience with government strategies to reduce cigarette-smoking shows that both the interventions and the behavior are highly complex. Many interventions have not been carefully evaluated, and methodologic difficulties have thwarted some of the studies that have been undertaken. A comprehensive, multipronged approach to smoking reduction appears to work best, but long-term problems still exist.
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, findings suggest that counseling and pharmacological therapies are effective (AHCPR, 1996; Tobacco Use and Dependence Clinical Practice Guideline Panel, 2000). The U.S. Public Health Service issued a Clinical Practice Guideline (Tobacco Use and Dependence Clinical Practice Guideline Panel, 2000) based upon the recommendations of an expert panel. They reviewed nearly 6,000 peer-reviewed articles and recommended that all tobacco users should be offered treatment since effective treatments exist: institutionalizing consistent identification, documentation, and treatment of all tobacco users; brief treatment is effective; greater intensity of counseling is more effective; three types of counseling and five pharmacotherapies were found to be effective. This approach was evaluated for tobacco cessation, but in modified form might also be effective for prevention.
Many 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. One exemplary study of school-based smoking prevention, the Hutchinson Smoking Prevention Project (HSPP) (Peterson et al., 2000) sponsored by the National Cancer Institute, is described above. This 15-year study, in 40 school districts of Washington state that were randomly assigned to intervention or control groups, involved 8,388 third graders who were followed to 2 years after high school with 94% follow-up. The authors concluded “there is no evidence from this trial that a school-based social-influences approach is effective in the long-term deterrence of smoking among youth.”
Similarly, an assessment of policy interventions in a school setting was found to have limited impact. Based on the observation that organizational smoking policy may be a potentially effective way to influence smoking behavior in worksites (Borland et al., 1990), Bowen et al. (1995) surveyed 239 schools as to their smoking policies. They identified three types of policies: a ban on smoking on school grounds; smoking allowed on school grounds; and smoking allowed in designated areas in the building. Their conclusion was: “current smoking policies may have limited ability to reduce student smoking.”
A scholarly review of government level approaches to tobacco use prevention and cessation by the Advocacy Institute (2000) found that although 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, physician 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
APPLICATION OF RESEARCH RESULTS
Much research is needed to complete the picture of how individual genetic endowments and physiological processes interact with individual personalities, development, other psychological characteristics and processes, and social status and relationships to affect health status. Simply put, how does the environment “get under the skin” (Taylor et al., 1997), and what can be done to optimize health (Ryff and Singer, 1998)? Such research will require the collaboration and cooperation of multiple disciplines. New research methods are likely to be required as multiple influences are considered simultaneously and as causes and effects are considered dynamically and systemically, rather than linearly.
To develop programs that are effective in modifying health behaviors, expanded efforts in all five phases (NHLBI, 1983) of intervention research are needed. These five phases include hypothesis generation, development of intervention methods, controlled intervention trials, studies in defined populations, and demonstration research (Chapter 7). Systematic clinical trials are needed to evaluate the value of behavioral and psychosocial interventions; in particular, more studies are needed that document the effects of these interventions on health, quality of life, and longevity. Studies suggest that interventions at multiple levels are more effective than interventions at single levels, but well-designed evaluations are necessary. Innovative methods and naturalistic experiments also will be necessary to evaluate community, organizational, and public policy interventions, and particularly multilevel interventions. Those methods will be critically important if knowledge from behavioral and psychosocial research is to be translated into applications in more natural settings.
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.
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 promote 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, 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 sider 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, quasiexperimental methods, community-based participatory research, and development of new research methods are necessary to advance knowledge in these areas.
- Abt. Independent Evaluation of the Massachusetts Tobacco Control Program. Cambridge, MA: Abt Associates; 1997.
- Adler N, Boyce T, Chesney M, Cohen S, Folkman S, Kahn R, Syme L. Socioeconomic status and health: The challenge of the gradient. American Psychologist. 1994;49:15–24. [PubMed: 8122813]
- Advocacy Institute. Making The Case: State Tobacco Control Policy Briefing Papers. 1707 L St., NW, Suite 400, Washington, DC 20036: 2000.
- AHCPR (Agency for Health Care Policy and Research) Smoking Cessation Clinical Practice Guideline. Journal of the American Medical Association. 1996;275(16):1270–1280. [PubMed: 8601960]
- Albright CL, Altman DF, Slater MD, Maccoby N. Cigarette advertisements in magazines: Evidence for a differential focus on women's and youth magazines. Health Education Quarterly. 1988;15:225–233. [PubMed: 3378906]
- Altman DG, Wheelis AY, McFarlane M, Lee H, Fortmann SP. The relationship between tobacco access and use among adolescents: A four community study. Social Science and Medicine. 1999;48:759–775. [PubMed: 10190639]
- Anderson BJ. Involving family members in diabetes treatment. In: Rubin RR, editor. Practical Psychology for Diabetes Clinicians. Alexandria, VA: American Diabetes Association; 1996. pp. 43–50.
- Anderson RM, Funnell MM, Butler PM, Arnold MS, Fitzgerald JT, Feste CC. Patient empowerment. Results of a randomized controlled trial. Diabetes Care. 1995;18:943–949. [PubMed: 7555554]
- Bal DG, Kizer KW, Felten PG, Mozar HN, Niemeyer D. Reducing tobacco consumption in California. Development of a statewide anti-tobacco use campaign. Journal of the American Medical Association. 1990;264:1570–1574. [PubMed: 2395199]
- Berkman L, Kawachi I, editors. Social Epidemiology. New York: Oxford University Press; 2000.
- Bonnie R.The efficacy of law as a paternalistic instrument. In: Melton G, editor. Nebraska Symposium on Human Motivation, 1985: The Law as a Behavioral Instrument; Lincoln, NE: University of Nebraska Press; 1986. pp. 131–211. [PubMed: 3915343]
- Bowan DJ, Kinne S, Orlandi M. School policy in COMMIT: A promising strategy to reduce smoking by youth. Journal of School Health. 1995;65:140–144. [PubMed: 7603051]
- Centers for Disease Control and Prevention. Decline in cigarette consumption following implementation of a comprehensive tobacco prevention and education program—Oregon, 1996–1998. Morbidity and Mortality Weekly Report. 1999;48:140–143. [PubMed: 10077459]
- Chaloupka FJ, Grossman M. Working Paper No. 5740. Cambridge, MA: National Bureau of Economic Research; 1996. Price, tobacco control policies, and youth smoking.
- Chambless DL, Hollon SD. Defining empirically supported therapies. Journal of Consulting and Clinical Psychology. 1998;66:7–18. [PubMed: 9489259]
- Cinciripini PM, Lapitsky L, Seay S, Wallfisch A, Kitchens K, Van Vunakis H. The effects of smoking schedules on cessation outcome: Can we improve on common methods of gradual and abrupt nicotine withdrawal? Journal of Consulting and Clinical Psychology. 1995;63:388–399. [PubMed: 7608351]
- Cinciripini PM, Lapitsky LG, Wallfisch A, Mace R, Nezami E, Van Vunakis H. An evaluation of a multicomponent treatment program involving scheduled smoking and relapse prevention procedures: Initial findings. Addictive Behaviors. 1994;19:13–22. [PubMed: 8197889]
- Cohen S, Herbert TB. Health psychology: Psychological factors and physical disease from the perspective of human psychoneuroimmunology. Annual Review of Psychology. 1996;47:113–142. [PubMed: 8624135]
- Cohen S, Tyrrell DA, Smith AP. Psychological stress and susceptibility to the common cold. New England Journal of Medicine. 1991;325:606–612. [PubMed: 1713648]
- Compas BE, Haaga DF, Keefe FJ, Leitenberg H, Williams DA. Sampling of empirically supported psychological treatments from health psychology: Smoking, chronic pain, cancer, and bulimia nervosa. Journal of Consulting and Clinical Psychology. 1998;66:89–112. [PubMed: 9489263]
- Cromwell J, Bartosch WJ, Fiore MC, Hasselblad V, Baker T. Cost-effectiveness of the clinical practice recommendations in the AHCPR guideline for smoking cessation. Journal of the American Medical Association. 1997;278:1759–1766. [PubMed: 9388153]
- Delamater AM, Bubb J, Davis SG, Smith JA, Schmidt L, White NH, Santiago JV. Randomized prospective study of self-management training with newly diagnosed diabetic children. Diabetes Care. 1990;13:492–498. [PubMed: 2351027]
- Emery S, Gilpin EA, White MM, Pierce JP. How adolescents get their cigarettes: Implications for policies on access and price. Journal of the National Cancer Institute. 1999;91:184–186. [PubMed: 9923862]
- Evans N, Farkas A, Gilpin E, Berry C, Pierce JP. Influence of tobacco marketing and exposure to smokers on adolescent susceptibility to smoking. Journal of the National Cancer Institute. 1995;87:1538–1545. [PubMed: 7563188]
- Fawzy FI, Fawzy NW, Arndt LA, Pasnau RO. Critical review of psychosocial interventions in cancer care. Archives of General Psychiatry. 1995;52:100–13. [PubMed: 7848046]
- Flay BR. Psychosocial approaches to smoking prevention: A review of findings. Health Psychology. 1985;4:449–488. [PubMed: 3908090]
- Gilpin EA, Pierce JP, Rosbrook B. Are adolescents receptive to current sales promotion practices of the tobacco industry? Preventive Medicine. 1997;26:14–21. [PubMed: 9010893]
- Glynn TJ. essential elements of school-based smoking prevention programs. Journal of School Health. 1989;59:181–188. [PubMed: 2739360]
- Hall SM, Munoz RF, Reus VI. Cognitive-behavioral intervention increases abstinence rates for depressive-history smokers. Journal of Consulting and Clinical Psychology. 1994;62:141–146. [PubMed: 8034816]
- Helegeson VS, Cohen S. Social support and adjustment to cancer: Reconciling descriptive, correlational, and intervention research. Health Psychology. 1996;15:75–83. [PubMed: 8681922]
- Hermann G, Beck FM, Sheridan JF. Stress-induced glucocorticoid response modulates mononuclear cell trafficking during an experimental influenza viral infection. Journal of Neuroimmunology. 1995;56:179–186. [PubMed: 7860713]
- Hill RD, Rigdon M, Johnson S. Behavioral smoking cessation treatment for older chronic smokers. Behavior Therapy. 1993;24:321–329.
- Hughes JR, Goldstein MG, Hurt RD, Shiffman S. Recent advances in the pharmacotherapy of smoking. Journal of the American Medical Association. 1999;281:72–76. [PubMed: 9892454]
- Hunt WA, Barnett LW, Branch LG. Relapse rates in addiction programs. Journal of Clinical Psychology. 1971;27:455–456. [PubMed: 5115648]
- Hurt RD, Sachs DPL, Glover ED, Offord KP, Johnston JA, Dale LC, Khayrallah MA, Schroeder DR, Glover PN, Sullivan CR, Crogan IT, Sullivan PM. A comparison of sustained-released buproprion and placebo for smoking cessation. New England Journal of Medicine. 1997;337:1195–1202. [PubMed: 9337378]
- IOM (Institute of Medicine) Health and Behavior: Frontiers of Research in the Biobehavioral Sciences. Hamburg DA, Elliott GR, Parron DL, editors. Washington: National Academy Press; 1982.
- Jason LA, Berk M, Schnopp-Wyatt DL, Talbot B. Effects of enforcement of youth access laws on smoking prevalence. American Journal of Community Psychology. 1999;21:143–160. [PubMed: 10425697]
- Jeffery RW, Drewnowski A, Epstein LH, Stunkard AJ, Wilson T, Hill R. Long-term maintenance of weight loss: Current status. Health Psychology. 2000;19:5–16. [PubMed: 10709944]
- Kaplan GA, Keil JE. Socioeconomic factors and cardiovascular disease: A review of the literature. Circulation. 1993;88:1973–1998. [PubMed: 8403348]
- Keefe FJ, Caldwell DS. Cognitive behavioral control of arthritis pain. Medical Clinics of North America. 1997;81:277–290. [PubMed: 9012765]
- Keeler TE, Hu TW, Barnett PG, Manning WG. Taxation, regulation, and addiction: A demand function for cigarettes based on time-series estimates. Journal of Health Economics. 1993;12:1–18. [PubMed: 10126486]
- Klein KB, Spiegel D. Modulation of gastric acid secretion by hypnosis. Gastroenterology. 1989;96:1383–1387. [PubMed: 2714570]
- Lalonde MA. New Perspectives on the Health of Canadians. A Working Document. Ottawa: Information Canada; 1974.
- Lewit EM, Coate D, Grossman M. The Effects of Government Regulations on Teenage Smoking. Journal of Law and Economics. 1981;24:545–569.
- Linden W, Stossel C, Maurice J. Psychosocial interventions for patients with coronary artery disease: a meta-analysis. Archives of Internal Medicine. 1996;156:745–752. [PubMed: 8615707]
- Lorig K, Holman H. Arthritis self-management studies; A twelve year review. Health Education Quarterly. 1993;20:17–28. [PubMed: 8444622]
- Mackenbach JP, Stronks K, Kunst AE. The contribution of medical care to inequalities in health: Differences between socio-economic groups in decline of mortality from conditions amenable to medical intervention. Social Science and Medicine. 1989;29:369–376. [PubMed: 2762863]
- Manning WG, Keeler EB, Newhouse JP, Sloss EM, Wasserman J. The Costs of Poor Health Habits. Cambridge, MA: Harvard University Press; 1991.
- Marcus BH, Blair SN, Dubbert PM, Dunn AL, Forsyth LH, McKenzie TL, Stone EJ. Physical activity behavior change: Issues in adoption and maintenance. Health Psychology. 2000;19:32–41. [PubMed: 10709946]
- Matthews K, Kelsey S, Meilahn E, Kuller LH, Wing RR. Educational attainment and behavioral and biologic risk factors for coronary heart disease in middle-aged women. American Journal of Epidemiology. 1989;129:1132–1144. [PubMed: 2729252]
- McEwen B. Protective and damaging effects of stress mediators. New England Journal of Medicine. 1998;338:171–179. [PubMed: 9428819]
- McEwen BS, Stellar E. Stress and the individual: Mechanisms leading to disease. Archives of Internal Medicine. 1993;153:2093–2101. [PubMed: 8379800]
- McGinnis JM, Foege WH. Actual causes of death in the United States. Journal of the American Medical Association. 1993;270:2207–2212. [PubMed: 8411605]
- McNabb WL, Quinn MT, Murphy DM, Thorp FK, Cook S. Increasing children's responsibility for diabetes self-care: The In Control study. Diabetes Educator. 1994;20:121–124. [PubMed: 7851224]
- Meyer TJ, Mark M. Effects of psychosocial interventions with adult cancer patients: A meta-analysis of randomized experiments. Health Psychology. 1995;14:101–108. [PubMed: 7789344]
- NHLBI (National Heart, Lung, and Blood Institute) Guidelines for Demonstration And Education Research Grants. Washington, DC: National Institutes of Health; 1983.
- NIH Technology Assessment Panel. Integration of behavioral and relaxation approaches into the treatment of chronic pain in insomnia. Journal of the American Medical Association. 1996;276:313–318. [PubMed: 8656544]
- Ockene JK, Emmons K, Mermelstein R, Perkins KA, Bonollo D, Hollis JF, Vorhees C. Relapse and maintenance issues for smoking cessation. Health Psychology. 2000;19:17–31. [PubMed: 10709945]
- Orleans CT, Boyd NR, Bingler R, Sutton C, Fairclough D, Heller D, McClatchey M, Ward JA, Graves C, Fleisher L, Baum S. A self-help intervention for African American smokers: Tailoring cancer information service counseling for a special population. Preventive Medicine. 1998;27(5 Pt 2):S61–S70. [PubMed: 9808825]
- Parker JC. Effects of stress management on clinical outcomes in rheumatoid arthritis. Arthiritis and Rheumatism. 1995;38:1807–1818. [PubMed: 8849353]
- Peterson AV Jr, Kealey KA, Mann SL, Marek PM, Sarason IG. Hutchinson smoking prevention project: long-term randomized tiral in school-based tobacco use prevention—results on smoking. Journal of the National Cancer Institute. 2000;92:1979–1991. [PubMed: 11121460]
- Pierce JP.The Effectiveness of Various Communication Strategies in Promoting Behavior Change. Presented at the Workshop on Health, Communications and Behavior of the IOM Committee on Health and Behavior: Research, Practice and Policy; Irvine, CA. 1999.
- Pierce JP, Gilpin EA. A historical analysis of tobacco marketing and the uptake of smoking by youth in the United States: 1890–1977. Health Psychology. 1995;14:500–508. [PubMed: 8565924]
- Pierce JP, Choi WS, Gilpin EA, Farkas AJ, Berry CC. Tobacco industry promotion of cigarettes and adolescent smoking. Journal of the American Medical Association. 1998a;279:511–515. [PubMed: 9480360]
- Pierce JP, Gilpin EA, Farkas AJ. Can strategies used by statewide tobacco control programs help smokers make progress in quitting? Cancer Epidemiology, Biomarkers and Prevention. 1998c;7:459–464. [PubMed: 9641487]
- Pierce JP, Gilpin EA, Emery SL, White MM, Rosbrook B, Berry CC. Has the California tobacco control program reduced smoking? Journal of the American Medical Association. 1998b;280:893–899. [PubMed: 9739973]
- Prochaska JO. Revolution in health promotion: Smoking cessation as a case study. In: Marlatt GA, Vandenbos GR, editors. Addictive Behaviors: Readings on Etiology, Prevention and Treatment. Washington, DC: American Psychological Association Press; 1997. pp. 361–375.
- Rose-Ackerman S. Tort law in the regulatory state. In: Schuck PH, editor. Tort Law and the Public Interest. New York: Norton; 1991. pp. 105–126.
- Ryden O, Nevander L, Johnsson P, Hansson K, Kronvall P, Sjoblad S, Westbom L. Family therapy in poorly controlled juvenile IDDM: Effects on diabetic control, self-evaluation and behavioral symptoms. Acta Paediatrica. 1994;83:285–291. [PubMed: 8038531]
- Ryff CD, Singer B. The contours of positive human health. Psychological Inquiry. 1998;9:1–28.
- Satin W, La Greca AM, Zigo MA, Skyler JS. Diabetes in adolescence: Effects of multifamily group intervention parent simulation of diabetes. Journal of Pediatric Psychology. 1989;14:259–275. [PubMed: 2754576]
- Schwartz JL. Methods of smoking cessation. Medical Clinics of North America. 1992;76:451–476. [PubMed: 1548971]
- Shiffman S. Smoking cessation treatment: Any progress? Journal of Consulting and Clinical Psychology. 1993;61:718–722. [PubMed: 8245269]
- Stevens VJ, Hollis JF. Preventing smoking relapse, using individually tailored skills training techniques. Journal of Consulting and Clinical Psychology. 1989;57:420–424. [PubMed: 2738215]
- Suchanek Hudmon K, Gritz ER, Clayton S, Nisenbaum R. Eating orientation, postcessation weight gain, and continued abstinence among female smokers receiving an unsolicited smoking cessation intervention. Health Psychology. 1999;18:29–36. [PubMed: 9925043]
- Taylor SE, Repetti RL, Seeman T. Health psychology: What is an unhealthy environment and how does it get under the skin? Annual Review of Psychology. 1997;48:411–447. [PubMed: 9046565]
- Thomas-Dobersen DA, Butler-Simon N, Fleshner M. Evaluation of a weight management intervention program in adolescents with insulin-dependent diabetes mellitus. Journal of the American Dietetic Association. 1993;93:535–540. [PubMed: 8315162]
- Tobacco Use and Dependence Clinical Practice Guideline Panel, Staff, and Consortium Representatives. A Clinical Practice Guideline For Treating Tobacco Use and Dependence: A US Public Health Service report. Journal of the American Medical Association. 2000;28:3244–3254. [PubMed: 10866874]
- United States Department of Health, Education, and Welfare. DHEW Publication Number (PHS) 79-55071. Washington, DC: U.S. Government Printing Office; 1979. Healthy People.
- USDHHS (U.S. Department of Health and Human Services) Clinical Practice Guideline, No 18. Smoking Cessation. Rockville, MD: Agency for Health Care Policy and Research. Centers for Disease Control and Prevention; 1996. AHCPR Publication No. 96-0692.
- Velicer WF, Prochaska JO, Fava JL, Laforge RG, Rossi JS. Interactive versus noninteractive interventions and dose-response relationships for stage-matched smoking cessation programs in a managed care setting. Health Psychology. 1999;18:21–28. [PubMed: 9925042]
- Vicusi WK. Fatal Tradeoffs. New York: Oxford University Press; 1992.
- Warner KE. Smoking and health implications of a change in the federal cigarette excise tax. Journal of the American Medical Association. 1986;255:1028–1032. [PubMed: 3945014]
- Whorwell PJ, Prior A, Farragher EB. Controlled trial of hypnotherapy in the treatment of severe refractory irritable bowel syndrome. Lancet. 1984;2(8414):1232–1234. [PubMed: 6150275]
- Wilkinson RG. Unhealthy Societies: The Afflictions of Inequality. London: Routledge; 1996.
National Academies Press (US), Washington (DC)
Institute of Medicine (US) Committee on Health and Behavior: Research, Practice, and Policy. Health and Behavior: The Interplay of Biological, Behavioral, and Societal Influences. Washington (DC): National Academies Press (US); 2001. 8, Findings and Recommendations.