Primordial and primary prevention programs for cardiovascular diseases: from risk assessment through risk communication to risk reduction. A review of the literature

The aim of this study was to identify and reflect on the methods employed by studies focusing on intervention programs for the primordial and primary prevention of cardiovascular diseases. The PubMed, EMBASE, SciVerse Hub-Scopus, and Cochrane Library electronic databases were searched using the terms ‘effectiveness AND primary prevention AND risk factors AND cardiovascular diseases’ for systematic reviews, meta-analyses, randomized clinical trials, and controlled clinical trials in the English language. A descriptive analysis of the employed strategies, theories, frameworks, applied activities, and measurement of the variables was conducted. Nineteen primary studies were analyzed. Heterogeneity was observed in the outcome evaluations, not only in the selected domains but also in the indicators used to measure the variables. There was also a predominance of repeated cross-sectional survey design, differences in community settings, and variability related to the randomization unit when randomization was implemented as part of the sample selection criteria; furthermore, particularities related to measures, limitations, and confounding factors were observed. The employed strategies, including their advantages and limitations, and the employed theories and frameworks are discussed, and risk communication, as the key element of the interventions, is emphasized. A methodological process of selecting and presenting the information to be communicated is recommended, and a systematic theoretical perspective to guide the communication of information is advised. The risk assessment concept, its essential elements, and the relevant role of risk perception are highlighted. It is fundamental for communication that statements targeting other people’s understanding be prepared using systematic data.


' INTRODUCTION
The aging of the population, which has occurred as a result of the increased population and life expectancy, has led to an increase in the mortality due to noncommunicable diseases (NCDs). According to estimates from the World Health Organization in 2012, 68% of the 56 million global deaths were caused by NCDs, of which 46% were due to cardiovascular diseases (CVDs) (1). In Brazil, as stated by the Ministry of Health, NCDs were the cause of a large proportion of deaths from 2009-2013; CVDs were the main cause of death, at nearly 30%, of which 20% were due to ischemic heart disease, cerebrovascular disease, and high blood pressure (2).
NCDs have a long natural history, a long latent period, and a slow, lengthened and continuous clinical course, among other features, and result from exposure to a variety of risk factors (3). According to the World Health Organization, nearly a third of the world's deaths can be attributed to ten risk factors, and the most frequent ones, e.g., high blood pressure, tobacco use, high blood glucose, high blood cholesterol, physical inactivity, overweight, and obesity, are related to the development of NCDs (4). Current knowledge has thus established the value of primordial prevention actions, which aim to prevent the development of disease risk factors, and of primary prevention actions, which aim to modify existing risk factors to prevent the development of diseases. These preventive approaches have become the basis of intervention community programs that focus on promoting cardiovascular health and preventing CVDs; however, scientific evidence is needed to demonstrate the effectiveness of the community approach to promoting public health (5,6).
Systematic reviews on the effectiveness of multiple risk factor interventions for preventing CVDs suggest that they may be effective for people at high risk of CVDs, may not be particularly effective for people at low risk of CVDs, and may achieve favorable changes in overall CVD risk, among other findings; however, considerable uncertainty remains (7,8). Methodologic differences in the design or analysis may account for the lack of successful outcomes. A better understanding of which interventions are effective and further research on the most effective and efficient ways to change the health behavior of populations are needed to improve the outcomes of future interventions (5).
Accordingly, the aim of this study was to identify and reflect on the methods employed in studies focused on intervention programs targeting the primordial and primary prevention of CVDs.

Search strategy and study selection
The PubMed, EMBASE, SciVerse Hub-Scopus, and Cochrane Library electronic databases were searched using the terms 'effectiveness AND primary prevention AND risk factors AND cardiovascular diseases' for systematic reviews, meta-analyses, randomized clinical trials and controlled clinical trials limited to studies in the English language. After identification and screening, 50 primary studies and eight systematic reviews and metaanalyses met the eligibility criteria. The medians of the variables 'follow-up period' and 'individual number' in the primary studies were 24 months and 1174 individuals, respectively, and were considered criteria for study inclusion (Figure 1).

Eligibility criteria
Populationadults exposed to cardiovascular risk factors, with or without a diagnosis of cardiovascular disease; Interventioncommunity-or individual-level educational program, with or without therapeutic features, focused on cardiovascular risk factors: smoking, dietary behaviors, regular physical activity, and risk perception associated with overweight, arterial hypertension, metabolic disease, and familial inheritance; Controladults exposed to cardiovascular risk factors, with or without a diagnosis of cardiovascular disease, who were not exposed to intervention; Outcomeschange in attitudes, knowledge, behavior, perceptions, and biologic measures.

Exclusion criteria
Educational interventions targeting specific groups of diseases, conducted at work sites or second and tertiary healthcare units, or based only on electronic media.
Descriptive analyses and study syntheses of strategies, models, frameworks, applied activities, and measurement of variables were conducted, referring to studies of public health researchers affiliated with the University of Oxford.
As this article was based on studies available in the public domain, application to an Ethical Committee was not required.

' RESULTS
A community approach was employed by seven studies (9,10,11,12,13,14,15), applying principles from the social learning theory, community activation, the stage theory of innovation, the theory of planned behavior, the PRECEDE-PROCEED model, and other methods aiming to change both individual behavior and the environment, organizations, and policies to support individuals' heathy choices. The activities included educational programs on factors related to cardiovascular risk topics provided through multiple educational channels and instruments, community organization and activation, creation of social and institutional support for educational goals, and environmental changes; some studies conducted risk factor screening and targeted improvements in preventive services.
Ten studies chose a community and individual strategy (16,17,18,19,20,21,22,23,24,25) based on social learning, diffusion of innovation, social development, persuasive communication, and models involving community leaders and institutions. These studies shared similar hypotheses, although with distinct characteristics, about the roles of individuals, communities, and the physical and social environment. The activities included integration of occupational health and primary care services, an individual approach to health care services, promotion of healthy lifestyle campaigns, continuous training programs for health teams, and establishment of guidelines for diagnostic procedures, treatment, and healthy lifestyle counseling for application in health services, as well as environmental interventions.
The theoretical foundations of the two studies applying an individual strategy (26,27) were the stages of change model, motivational interviewing, and behavioral therapy, and the activities implemented were comprehensive individual care and healthy lifestyle counseling in general practice centers (Table 1).
Heterogeneity was observed between the studies regarding the methodology of the outcome evaluation, not only in the selected domains but also in the indicators used to measure the variables (Table 2).
Other features of the studies were noted: a predominance of repeated cross-sectional survey design, the use of rural and urban settings, the inclusion of communities with high rates of poverty and low educational levels, diverse age groups and variability related to the randomization unit when randomized procedures were implemented as part of the sample selection criteria. Furthermore, specifics related to variable measures, limitations, and confounding factors were observed (Tables 3 and 4).

' DISCUSSION
The observed heterogeneity between studies is a fundamental issue. Researchers examined the results of programs targeting primordial and primary prevention of CVD and attempted to identify the determinants of their success or failure. These determinants included specific population characteristics, matching of intervention and control communities, and the characteristics, exposure time, follow-up length, and evaluation method of the intervention. In addition, they addressed two questions: ''what type or model of intervention is the most effective in achieving improvements in the cardiovascular health of the population'' and ''which is the best evaluation program method'' (5,8).  Television series about healthy heart-related themes, food labeling and nutrition education with a major grocery retailer, a restaurant and canteen scheme to increase the availability of healthy food choices and smoke-free areas, and a worksite health promotion program. Puska P et al., 1983 C Behavioral-social model of community intervention: improved preventive services to help people identify their risk factors and to provide appropriate attention and services; information to educate people about the relationship between behaviors and their health; persuasion to motivate people and to promote the intention to adopt the healthy action; training to increase the skills of self-management, environmental control and necessary action; social support to help people maintain the initial action; environmental change to create opportunities for healthy actions and improve unfavorable conditions; community organization to mobilize broad-range changes in the community to support the adoption of new lifestyles in the community.
Educational activities through the mass mediaproduction of educational material about health and support to campaigns and community meetings; training programs to local staff -doctors, nurses, social workers, teachers, volunteer organization representatives and informal leaders; reorganization of preventive services through formal decisions, training, demonstrations, materials and guideline provision; activities with community organizations -medical and women's associations, sport clubs, food industries and groceries; monitoring project development -information systems to assess the intervention. The project was designed to create a self-sustaining health promotion structure based on community organizations that remained at the end of the intervention.
Intervention targeted all residents through multiple educational channels: interpersonal meetings, classes and correspondence courses, distribution of print media products through direct mail and worksites and medical care providers, programs in mass media, and materials targeting low-literacy and low-income individuals. The model postulates that a reduction in cardiovascular diseases can be achieved through changes in related risk behaviors and that behavioral changes are expected to result from changes in individuals' psychosocial determinants -awareness, attitudes, social influences, self-efficacy expectations and stages of change -through sufficient, tailored and effective activities with community participation, intersectorial collaboration, adjustment to the current situation, long-term continuation of the project, a multi-media and multi-method strategy and environmental changes.
Personal and group sessions with written, tailored information communicated via mass media; computertailored nutrition education, nutrition education tours in super-markets, food labeling, promotion of physical activity, regional campaign to promote physical activity among individuals over 55 years, television programs, walking and bicycling clubs, walking and cycling campaigns, stop-smoking campaigns; activity development according to the characteristics of the target groups.

Wendel-Vos GCW et al., 2009
C + I The model postulates that a reduction in cardiovascular diseases can be achieved through changes in related risk behaviors and that behavioral changes are expected to result from changes in individuals' psychosocial determinants -awareness, attitudes, social influences, self-efficacy expectations and stages of change -through Personal and group sessions with written, tailored information communicated via mass media; computertailored nutrition education, nutrition education tours in super-markets, food labeling, promotion of physical activity, regional campaign to promote physical activity among individuals over 55 years, television programs, C + I Social modeling and diffusion of innovation theories; the North Karelia Project was the primary model of practical application. Study hypothesis -supposition that sustained behavior change requires both the stimulation of individuals to attempt behavior change and a change in the physical and social environment to support individuals who are trying to change.
Television programs, radio interviews, newspaper feature articles in the model of 'behavioral journalism'intervention techniques that publicize the healthy behavior of real community people. Competitionssmoking cessation, physical activity and weight control. Environmental improvement -creating smoke-free restaurants, implementing a menu-labeling program for restaurants, cafeterias and other suppliers of ready-to-eat food and advocating for the construction of multi-use trails as a way to increase public opportunities for daily physical activity. Lupton BS et al., 2002 C + I Learning by doing rather than traditional health promotion; local empowerment, which emphasizes the potential of the individual and the community to take responsibility in making decisions, prioritizing and achieving power over one's own destiny.

Study Design
Most studies included in this article employed a cohort study and/or a repeated cross-sectional design.
Although randomized controlled trials are considered the gold standard for assessing the effectiveness of certain types of interventions, there are several restrictions to their use when evaluating health promotion initiatives (28). To assess the impact of community trials, studies can adopt a cohort design, a repeated cross-sectional survey design, or both simultaneously. The results based solely on a cohort study may not be representative of the target population, even if the population of interest comprises individuals residing in the community during the intervention, because the cohort sample is typically a self-selected subset of a group that is willing to be followed. Survey designs should preferably comprise independent samples with the same age and socioeconomic distribution that are ideally randomized and representative of the community (29,5).

Strategies
Two main strategies were employed by the studies included in this review, each with its advantages and disadvantages.
Individually targeted interventions may be of limited use in community programs because the participation of individuals is generally low, leading to a small impact at the population level. In community interventions, well-designed mass media campaigns are usually effective for increasing basic knowledge but ineffective for correcting misconceptions, and public policy changes probably achieve the best impact concerning cost effectiveness. There was no agreement regarding the duration of exposure to the intervention activities, as the amount of time depended on the nature of the intervention and the characteristics of the target population. One important issue when conducting community intervention programs is the intervention's sustainability, which is directly related to several factors. In brief, the simpler and cheaper an intervention is, and the higher the proportion of the community population covered by the intervention, the more sustainable a program will be. Additionally, sustainability is indirectly related to the intervention intensity; although the intensity should be high enough to produce changes (29), increased intensity usually leads to higher costs, more difficulty and often burnout among workers and participants.

Theories and Frameworks
The studies in this review applied different theories and frameworks that aimed to explain individual behavior and trends within populations.
The social learning 1 theory states that behavior change can be achieved through intense exposure to ideal or archetype models. Furthermore, it considers the influence of personal experience, observed or otherwise transferred, and the important role of self and group efficacy in changing behaviors in addition to the necessity of a supportive social setting and the development of skills to maintain new attitudes and practices.
The theory of planned behavior 2 assumes that individuals are typically rational and systematically use the information available to them. In this theory, individuals progress through several steps to achieve behavior changefrom awareness, attitudes and knowledge acquisition to motivation, skill development and action. Additionally, this theory states that the prevailing subjective norms in the community have a substantial impact on the health-related behaviors of  MRFIT, 1990 Cohort/120 months Each death certificate was independently coded by two nosologists, and disagreements were adjudicated by a third nosologist.
the individuals and that self-management skills have to be learned to maintain adapted behaviors. Persuasive communication 3 aims to convince individuals to be more responsible for their own health through a sevenstep procedure: reviewing reality, analyzing values, surveying the sociocultural situation, mapping a mental matrix, focusing on target themes, constructing communication, and evaluating the effectiveness.
The PRECEDE-PROCEED 4 model of educational interventions is a framework that encompasses several dimensions of health and includes a large number of health professionals in planning and managing health educational programs. The initial phases, namely social, epidemiological, behavioral/ environmental, educational/organizational, and administration/ policy assessment, are followed by program implementation and an evaluation of its process, impact, and outcome.
Social market 5 theories are based on the marketing orientation concept, which states that the main task of an organization is to determine the needs and demands of a population and to address these needs through design, communication, pricing, and the delivery of appropriate and competitively viable products and services. To organize preventive health services, the audience has to be defined, messages have to be developed, and the most effective channels for acceptance have to be selected. These theories combine and apply elements of the theories and frameworks described above.
The stages of change 6 model emphasizes the importance of cognitive processes and the concept of self-efficacy and assumes that individuals progress through the following stages during the change process: precontemplation, contemplation, preparation, action, maintenance, and occasionally relapse.
The diffusion of innovation 7 theory provides an understanding of how new ideas or behaviors are introduced and accepted by a community. This theory states that individuals advance through different stages-awareness, interest, persuasion, decision, and adoption-before changing their behavior; thus, individuals adopt new behaviors at different rates and respond to different methods of intervention. This model is similar to that of stages of change concerning the assumption that individuals progress through several stages before achieving behavior change. The main distinction between the two is that the stages of change model focuses on behavior change at the individual level, whereas diffusion of innovation focuses on behavior change in a population (5,30).

Interventions
Although several approaches can be employed to develop intervention activities, as shown by the studies included in this review, the essential aim of these activities is to communicate risk. This communication includes a challenging process of ensuring that risk assessments and risk management information are understandable to individuals, community groups, and professionals engaged in intervention activities.
To make reasonable decisions, individuals have to understand the risks and benefits associated with alternative courses of action, the limits of their own knowledge and the various recommendations of experts. Health risk decisions are influenced not only by cognitive processes and objectively communicated information but also by emotions, individual differences, culture, and social processes; however, it is important to ensure a correct understanding to prompt and encourage people's ability to think about their decisions.
Individuals who provide health information should have an understanding of what the targeted population knows, what they need to know, and how they should interpret the messages; a systematic theoretical perspective should guide how information is communicated. Studies point to three main approaches to communicating information: One approach is to use a mental model analysis, 8 which addresses differences between lay mental models and expert mental models. This analysis enables the identification of lay beliefs that would not have occurred to the experts, reduces the chances of omitting critical concepts and minimizes the clutter created by irrelevant information; furthermore, it illustrates the terms that laypeople use to express their beliefs.
Additionally, calibration analysis can be conducted to provide people the appropriate degree of confidence in their beliefs regarding situations in which they maintain false beliefs, as these could lead to incorrect behavior, or in which they lack confidence in the right beliefs. Confidence in the appropriate beliefs is needed to perform desired actions. Misconceptions can lead to incorrect conclusions even among presumably well-informed people, therefore deserving special attention in communication.
Finally, value-of-information analysis 9 provides insight into the type of information that would have the largest possible impact on future decisions.
Once the message has been selected, it must be presented in a comprehensible way. Accordingly, terms that people use to understand concepts and mental models that people use to combine concepts must be included; In addition, results of research on text comprehension must be considered.
Effective risk communication can help people reduce their health-related risks and can help them obtain more benefits in response to risks to which they are exposed. Ineffective communication may not only fail to provide these advantages but may also lead to inappropriate decisions by omitting key information or not arguing against false beliefs, even leading to opportunity costs. Poor communication can create a larger impact on public health than the risks they aim to describe by causing undue alarm or complacency.
As all individuals have experience in dealing with risks, eliciting others' beliefs may seem straightforward. However, this is often not the case; communicators' intuitions about people's risk perception cannot be trustedthere is no alternative to empirical validation (31).

Risk assessment and risk measurement
In addition to the observed heterogeneity between studies regarding the measurement of outcomes, there were differences in risk perception.
A risk assessment is the systematic scientific characterization of potential adverse effects caused by human exposures to dangerous agents or situations; both quantitative and qualitative estimates, as well as strength of the evidence, are essential to risk characterization. A fundamental issue in risk assessment is risk perception, which is an individual's degree of understanding of health-related risks. Individuals react very differently to information about harmful situationsone event can be accepted by one individual and not accepted by another, and understanding these responses is essential to developing risk management options (32).

Quantitative estimates
Studies show that lay estimates of risk are subject to biases. Few studies directly associate these biases with inappropriate risk decisions or suggest that people wait for accurate information to establish their decision models. Accurate risk estimates are necessary but not sufficient for effective decisions, as estimates alone do not inform people about what actions are possible, what objectives are worth pursuing, nor what risks are worth concern. Other characteristics of the quantitative perception of risks have been noted by experts: the internal consistency of relative frequency estimates, influence of anchors provided by investigators, less dispersion of subjects' estimates in statistical evaluations, miscalibration of confidence judgements, and availability bias. Availability bias implies that the more visible an event is, through personal or reported media experiences, the higher an estimate of risk it will receive, and this relationship seems to reflect a general tendency to estimate the frequency of events by the ease with which they are remembered or imagined. Other studies point to response mode problems: researchers' reliance on verbal quantifiers to communicate and elicit risk estimatese.g., terms such as ''rare'' or ''very likely'' mean different things to different people and even to the same people in different contexts; nonlinear relationships between quantitative and qualitative scales; the rather insensitive effect of the provided anchors, which are employed with the assumption of improving peoples' performance regarding the correct range of estimates; and the dangers of applying a single response mode (31).
Assessing the accuracy of lay risk estimates relies not only on a proper response model but also on a pattern against which responses can be compared. Peoples' performance might vary widely and be more difficult to evaluate when they are faced with risks that have an unclear magnitude; additionally, for many decisions, peoples' understanding of population-wide risks is less relevant than their understanding of personal risks. Investigators have identified a perceived invulnerability, i.e., an optimism bias, when they evaluate how individuals judge their risks in relation to others in the same circumstances and in situations under some personal controlmost people perceive that they face less risk than others (31).
Studies providing measures of risk perceptions assume that people define risk as the probability of an adverse event occurrence. Nevertheless, observations of scientific practice show that risk can be presented through a variety of meanings, even among professionals: the characterization of risk through a discrete instead of a continuous descriptor or alternatively through a safe or unsafe descriptor conveys rather little information, and without more detail, one does not know what the investigator means by a certain descriptor. Studies point to different risk definitions as a partial cause of the inconsistency between investigators and laypeople regarding the magnitude of risks in society.
The multidimensional nature of risk affects how it is judged, which means that although hazards may be similar in many ways, they may evoke quite different responses. Much research and speculation has been applied to test hypotheses that lead to a descriptive theory of risk perceptions, a prescriptive guide to risk decisions or a scheme for predicting the public's response to new hazards or hazard reductions.
Regarding the role of perception about risk perceptions in public health, one assumption is considered fundamental: statements targeting other people's understanding must be constructed using systematic data because people can be harmed by inaccuracies in their risk perceptions and by inaccuracies in other people's beliefs about risk perception, particularly those of groups who communicate risks, such as health professionals (31).

Qualitative assessment
Scientific estimates of the magnitude of risk rely on a comprehensive specification of the conditions under which it is observed; any other scenario will generate answers related to the perception each individual has about the value of each missing detail. Ambiguous events enable responses to different questions and thus result in ambiguous responses. When people are asked to answer questions they do not understand, any relationship between their related beliefs and respective behavior will tend to be blurred and lead observers to false conclusions regarding how the information-transmission activity was developed.
In addition to the methodological importance, the details people infer can be particularly interesting and illustrate intuitive theories about risk that people invoke in personally meaningful ways when facing tasks (31).

' IMPLICATIONS FOR PRACTICE
Current evidence supports the notion that complementary strategies must be employed to improve the cardiovascular health of the population (33): -Individual approaches, which target healthy lifestyles and drug treatment when necessary, should be implemented while considering the following: that medical knowledge is based on biomedical rationality and is thus limited in addressing the complexity of the health-sickness process and that to be comprehensive, interventions focused on health promotion and on disease control should incorporate the autonomy, values, and preferences of the subjects regarding technical knowledge (34); -Healthcare system approaches that encourage, facilitate, and reward healthcare providers' efforts to improve health behaviors and health factors can also be employed; and -Population approaches that target changes in lifestyle can be conducted in schools, worksites, and communities and can include the development of public policies to support lifestyle changes.

' IMPLICATIONS FOR RESEARCH
Systematic qualitative studies that focus on information and communication and evaluate how participants perceive and respond to interventions could be of great value in shaping future interventions.