3. Concepts of Prevention – Prevention of Skin Cancer

Prevention is an umbrella term for measures aimed at reducing the occurrence and spread of diseases and the associated impact on morbidity and mortality in a society [2]. Prevention is directly related to a target disease and implies that it has specific causes that can be prevented by specific measures [3]. The main starting point is therefore the reduction or elimination of the causes of disease or the prevention of hazardous exposures [4].

The concept of prevention (originally disease prevention) developed in the 19th century from the debate on hygiene and public health.

One of the most commonly used terms, along with prevention, is “precaution.” This is an undefined legal term. It is not defined by law but can only be determined by interpretation. The term can be found in the coverage of daily needs (“Daseinsvorsorge": services of general economic interest provided by the state as “Gewährleistender"), financial security for old age (“Altersvorsorge,” § 33 SGB XII; contributions for a more equitable old-age provision, lifelong life annuity) and in insurance against the risks of illness as a safeguard in the event of illness. Precautionary expenditure is therefore the expenditure for insurance against future risks (insurance principle).

In the field of medical care, preventive measures are also often found under the term “Vorsorge.” In occupational medicine in particular, this term is enshrined in law in the Ordinance on Preventive Occupational Medicine (ArbMedVV). In the ArbMedVV, among other things, occupational medical preventive examinations are also used for cancer, as a paraphrase of various early cancer detection examinations.

The cancer screening programme introduced nationwide in 1971 was introduced at that time as “screening programme,” with the aim of bringing forward the time of diagnosis and the associated improvement in quality of life. The users often interpreted these preventive examinations in the sense of the above-mentioned insurance principle, so that the Federal Joint Committee (G-BA) has since then only spoken of prevention in its guidelines.

According to Rosenbrock and Michel (2007), the relevant goals of prevention include the avoidance, mitigation, or postponement of:

• Morbidity and mortality and the resulting losses in quality of life and restrictions in participation in social life.
• Direct medical costs of curation, rehabilitation, and social insurance.
• Indirect costs of illness due to reduced productivity, limited civic engagement, or welfare losses for society as a whole.

The prerequisite for the targeted prevention of a disease is knowledge of its pathogenetic dynamics, i.e. knowledge of the different stages of development and progression of the disease process, both in terms of the population and at the individual level, taking risk profiles into account [4].

Service providers in the field of prevention, whether in the health care system or in kindergartens, schools, or other living environments of children and adolescents, at the workplace, and in other areas, should be aware of the fundamentals of preventive action. A prerequisite for this is the definition of the term “health.” Health is defined following the World Health Organisation (WHO) 1946 and Hurrelmann [5] (Hurrelmann, 2003, p3. in [5]), page 8, as a

“state of the objective and subjective condition of a person, which is given when this person is in the physical, psychological and social areas of their development in harmony with their own possibilities and goals and the given external living conditions."

TThis includes all health-relevant areas of life, such as education, work, housing, nutrition, transport, environment, family, leisure, etc., as they are also described in the Prevention Act. Health and illness are not to be understood as absolute and unchangeable stages, but as continuous and dynamic processes, in which the balance of risk and protective factors is reexamined at every point in life history ([5], p. 147).

It follows from this understanding of health that patients and users of the health care system are not to be classified as objects of health care, but rather that they are to be understood above all in their role as perceiving and acting subjects or as experts of themselves, whose individual life contexts and needs shape their health-related ideas and decisions.

This perspective requires a target group- and lifeworld-oriented approach from the actors involved in prevention work. In the personal preventive counselling situation particularly, this means identifying people's personal and social resources in discussion and jointly finding ways to adopt preventive behaviour in order to maintain health or minimise risk factors.

In this patient-centered approach, it is incumbent upon health professionals to establish a genuine appreciative encounter, taking into account medical-ethical principles (right to self-determination; do no harm; care, assistance; equality and justice ([Beauchamp, C. et al. 2019]), 

in which neutral evidence-based and comprehensible information about prevention content and related information sources are conveyed.

Health promotion is often referred to in the context of prevention, especially in the primary prevention field. The term is historically younger than prevention and has developed with the health policy debates of the World Health Organization (WHO, Ottawa Charter) and under the influence of population and social science disciplines. The focus is on maintaining health by strengthening resources [6]. Health promotion aims to improve the individual's ability to cope with life and to promote the economic, cultural, social, and educational conditions for shaping life [4]. The prerequisite for this is knowledge of salutogenetic dynamics, i.e. the development and maintenance of health (as opposed to the avoidance of illness) at the individual level and in the collective [2].

Health promotion and disease prevention are complementary forms of intervention [7]. Both terms describe forms of interventions, i.e. targeted interventions or measures. However, they are based on different theoretical foundations and historical contexts. The aim of interventions in both prevention and health promotion is to achieve health gains for both the individual and the population. This involves influencing process dynamics, i.e. future events. Differences exist in the forms of intervention and their principles of action [4]. Prevention follows an avoidance strategy based on the reduction of risk factors, whereas health promotion follows a promotion strategy, i.e. the strengthening of resources and protective factors [2]. Health promotion precedes prevention in time, whereby a clear separation of health-promoting and preventive measures is not always possible and a stronger integration of both forms of intervention is sometimes called for [2].

Depending on the initial situation, prevention measures can be classified along different dimensions. The various starting points, dimensions, and the classification within them are fluid and should be regarded as complementary.

Prevention pursues staged goals, which can be differentiated into primordial, primary, secondary, and tertiary prevention along the developmental stages of a target disease.

Primordial Prevention

Primordial prevention begins even before primary prevention and is intended to prevent the development of social risk factors by influencing the healthy population with regard to living conditions and lifestyles in such a way that it is possible to maintain health [5].

Primary Prevention

Primary prevention targets healthy individuals or (sub)populations, or individuals without manifest symptoms [4]; [8].   It aims to prevent the recurrence of a (chronic) disease and to reduce the incidence of disease or accidents [9]; [8]. Different levels can be addressed, such as individuals, settings, or the population as a whole, and different starting points can be chosen, such as working towards the prevention or reduction of risk factors through individual behaviour or changing environmental factors that are causally involved in the development of disease.

Secondary Prevention

Secondary prevention aims at detecting the initial stage of a disease, the progression of which can be prevented or mitigated by diagnostic/therapeutic measures [4]; [8]. In terms of health policy, secondary prevention aims to reduce the incidence of manifest or advanced disease [7].

Temporally, secondary prevention starts even before symptoms or complaints appear. For this purpose, health checks, disease-specific early detection examinations or filter examinations (screenings) are carried out among defined population groups. The prerequisite is the clinically or epidemiologically proven additional benefit of early treatment (ibid.). In addition to early detection and early treatment, counselling on lifestyle changes can also be part of secondary prevention.

A key component of secondary prevention is screening. Screening includes recruiting apparently healthy participants, taking a medical history, and administering the screening test for early detection of the condition in question. Usually, advice on risk factors and prevention can also be given in this context. According to Morrison (1993), screening divides participants into “individuals with a low probability of having the disease" and “individuals with a high probability of having the disease,” with the second group undergoing confirmatory diagnostics to confirm the diagnosis.

Tertiary Prevention

Tertiary prevention is aimed at people with a manifest disease or condition and aims to prevent or alleviate any resulting loss of function [8]. Appropriate diagnostic and therapeutic measures are intended to prevent complications and consequential damage and to prevent relapses [10]; [4]. The distinction between medical-therapeutic treatment and a tertiary preventive measure can rarely be drawn clearly. It is a question of the goal of the intervention whether an intervention is understood as curative or preventive [4]. In this context, both curative and preventive orientation of the intervention can be counseled to avoid continued disease-causing behaviours/risk factors, etc.

Quaternary Prevention

Quaternary prevention (first described by Jamoulle, 1968) is the avoidance of unnecessary medical intervention or the prevention of overmedicalisation, but can also mean the prevention of unnecessary prevention [11]. It is aimed at people who feel ill, but doctors would describe an overwhelming proportion of these complaints as symptoms that cannot be medically explained. In the “four-field table" model (Figure Four-field table model), quaternary prevention is therefore placed at the point where a health disorder is present from the patient's point of view, but no disease is present from the doctor's point of view. Undoubtedly, the conscious and justified decision to forego further diagnostics and therapy is a difficult task for both sides. In this context, it is particularly important not to leave the patient alone with his or her illness, but to use communicative means in a trusting and appreciative atmosphere to find ways out of the illness together, based on the patient's personality or life history [12]; [13].

In addition to forms of medical prevention (e.g. early detection measures, vaccinations), a distinction can be made between two other approaches to preventive measures that involve the context in different ways: behavioural prevention and situational prevention.

Behavioural Prevention

Behavioural prevention is concerned with influencing individual behaviour and consumption patterns in such a way that health risks are reduced [8]. This is done through education and information, but also by strengthening health literacy so that people are empowered and motivated to avoid or positively influence potential risk factors in their personal lifestyle (von Kardorff, 1995; Graf, Starke and Nellen, 2008). Behavioural prevention should be combined with relationship prevention interventions if it is to be popular and effective [9].

Relational Prevention

Relational prevention is used to influence people's living, working and environmental conditions, thereby improving the framework conditions for risk avoidance or health maintenance [8]. Although this influence tends to be indirect, it often has lasting effects [4]. Numerous measures of health protection are part of the prevention of social risks, such as consumer health protection or occupational health and safety in companies [8]. Urban development that takes account of the health needs of local residents, such as the provision of shaded areas, is also considered to be a form of preventive action.

Another focus is set according to the risk of disease or the degree of danger. Traditionally anchored primarily in the field of community psychiatry, addiction support and addiction prevention, the "triadic specificity model" is also gaining importance in prevention in general. A distinction is made between universal, selective, and indicated prevention.

Triadic Specificity Model

Universal prevention targets the entire population or large subpopulations with measures that are generally considered useful or necessary. Target group-specific or selective prevention is aimed at specific segments of the population with a suspected or above-average risk of disease, whereby selection can be based on various criteria such as socio-demographic characteristics, contextual characteristics or membership of a risk group [6]; [4]. The higher the disease risk of the affected group of people, the more necessary the selective approach [6]. If the affected persons with whom a preventive measure is carried out already have the preliminary stage or early form of a disease, or if they have confirmed and individual risk factors of a disease, this is called targeted or indicated prevention [6]; [4]. It is sometimes difficult to distinguish between indicated prevention and curative measures.

The implementation of prevention measures can be understood as the provision of prevention services to the population (or a subpopulation). Four elements can be distinguished (John et al. 2015):

• (Oncological) target of the intervention
• Population included
• Performance of the prevention
• Outcome (successful motivation and implementation of preventive behaviour)

In order to examine whether (and if so, what effect) prevention measures have on the population, five dimensions can be measured.

• Reach: the proportion of the target population reached by the intervention
• Efficacy: effectiveness of the intervention under the study conditions
• Adoption: implementation of the intervention by prevention actors
• Implementation: degree to which the intervention is implemented according to its original idea
• Maintenance: the maintenance of the intervention under routine conditions

Against this background, it is important to avoid ineffective and unnecessary measures. In order to achieve this goal, the Association of the Scientific Medical Societies (AWMF) has adopted the “Choosing Wisely" campaign, launched by the American Board of Internal Medicine (ABIM) Foundation in 2012, for the avoidance of unnecessary medical services and a more responsible use of existing resources in the health care system, under the motto “Choosing Wisely Together" (https://www.awmf.org/fileadmin/user_upload/Medizinische_Versorgung/GKE/Manual_GKE_AWMF_V1-1.pdf) [16].

The figure "Prevention Matrix" summarizes the different dimensions of prevention. The planning of prevention measures can be oriented towards the course of the disease, the level of specification, or the level of intervention, or towards several of these dimensions simultaneously. In addition, a distinction can be made at all levels between medical behavioural prevention and relationship-based prevention (or a mixture of both). It is essential to pay attention to the effective implementation of and exchange with research results (translational process development) as well as the monitoring of the success of prevention measures (public health impact).

The concepts and approaches of prevention are shaped by their environment and are subject to constant change. In the field of primary prevention, for example, reference is often made to the historically more recent concept of health promotion, which is used in a sociological context and can be regarded as a complementary form of intervention. Health promotion follows a resource-oriented approach and aims to improve individual abilities to cope with life and to promote the economic, cultural, social, and educational conditions for shaping life [4].

The terminological classification presented here and the concepts listed form the theoretical framework for the contents elaborated in the following chapters. The basic structure of the guideline is based on the different types of prevention and is oriented along the course of the disease. Within the individual chapters, the focus is on specification (see e.g. 5.1.2), contextualisation (see e.g. 5.4.4), and intervention levels. Living environments such as the professional setting (see Chapter 7) , the medical setting (see e.g. Chapters 5.4.2.3 and 8.4), and educational institutions (see e.g. 5.4) are given special emphasis. The same applies to vulnerable target groups such as persons at risk and children and adolescents (see e.g. 5.1).

In order to promote a stronger patient orientation in the health care system and to contribute to a higher health literacy of its users, the guideline contains recommendations for the promotion of doctor-patient communication in the context of skin cancer prevention counselling (see chapter 5.4.2.3), early skin cancer detection, as well as information about the population and communicative strategies and communication channels in the field of primary and secondary prevention (see chapter 8.3).

Furthermore, against the background of the definitions and concepts listed, guiding themes can be formulated which are continuously taken into account in this guideline and will be of high importance in the future. These include:

• Basic research
• Focusing on the effectiveness of prevention measures
• Prioritisation of measures/interventions with target group specificity, setting orientation, sustainability, and contextualisation
• Project development with target groups and improving communication with target groups to promote acceptance and uptake
• Promotion of health literacy through evidence-based information and training materials as well as the development of corresponding curricula, improvement of doctor-patient communication, and creation of health-competent organisations/relationships. 
• Quality-driven promotion of digital transformation and new technologies.

This should sustainably increase the scope and quality of prevention research and practice and make a significant impact on health care. The boundaries between different disciplines are to be overcome, interfaces defined and used, and work carried out in an interdisciplinary and integrative manner with the involvement of a wide range of expertise. In this context, it is important to integrate all activities into the existing prevention landscape in Germany and to counteract the currently existing “patchwork" system by increasing networking and network formation.