Level of prevention

Concept of prevention

The goals of medicine are to promote health, to preserve health, to restore health when it is impaired, and to minimize suffering and distress. These goals are embodied in the word “prevention”. Successful prevention depends upon a knowledge of causation, dynamics of transmission, identification of risk factors and risk groups, availability of prophylactic or early detection and treatment measures, an organization for applying these measures to appropriate persons or groups, and continuous evaluation of and development of procedures applied. Preventive approach is the best approach to achieve these goals because preventive measures can be implemented with the joints efforts of health personal and the people at large at the family and the community level. The concept of preventive approach is broad based. There are four major levels of prevention i.e. primordial, primary, secondary and tertiary prevention. Each of these levels of prevention serves distinct purposes and involves specific interventions which are applied to entire population considering its physical, mental, social and spiritual domains.

Level of prevention

In modern day, the concept of prevention has become broad-based. Four level of prevention can be identified corresponding to different phase in development of diseases. They are as follows.

1. Primordial prevention
2. Primary prevention
3. Secondary prevention
4. Tertiary prevention

Primordial prevention

A new concept, is receiving special attention in the prevention of chronic diseases. This is primary prevention in its purest sense, that is, prevention of the emergence or development of risk factors in countries or population groups in which they have not yet appeared. For example, many adult health problems (e.g., obesity, hypertension) have their early origins in childhood, because this is the time when lifestyles are formed (for example, smoking, eating patterns, physical exercise). In primordial prevention, efforts are directed towards discouraging children from adopting harmful lifestyles. The main intervention in primordial prevention is through individual and mass education.

Primary prevention

Primary prevention can be defined as “action taken prior to the onset of disease which removes the possibility that the disease will ever occur”. It signifies intervention in the pre-pathogenesis phase of a disease or health problem (e.g., low birth weight) or other departure from health. Primary prevention may be accomplished by measures designed to promote general health and well-being, and quality of life of people or by specific protective measures.

The concept of primary prevention is now being applied to the prevention of chronic diseases such as coronary heart disease, hypertension and cancer based on elimination or modification of “risk-factors” of disease. The WHO has recommended the following approaches for the primary prevention of chronic diseases where the risk factors are established:

• Population (mass) strategy-: – directed at the whole population
• High-risk strategy: – care to individuals at special risk (clinical methods)

In summary, primary prevention is a “holistic” approach. It relies on measures designed to promote health or to protect against specific disease “agents” and hazards in the environment. Fundamental public health measures and activities such as sanitation; infection control; immunization; protection of food, milk, and water supplies; environmental protection; and protection against occupational hazards and accidents are all basic to primary prevention. Primary prevention has become increasingly identified with “health education” and the concept of individual and community responsibility for health.

Secondary prevention

Secondary prevention can be defined as “action which halts the progress of a disease at its incipient stage and prevents complications”. The specific interventions are early diagnosis (e.g. screening tests, case finding programmes) and adequate treatment. By early diagnosis and adequate treatment, secondary prevention attempts to arrest the disease process; restore health by seeking out unrecognized disease and treating it before irreversible pathological changes have taken place; and reverse communicability of infectious diseases. It may also protect others in the community from acquiring the infection and thus provide, at once, secondary prevention for the infected individuals and primary prevention for their potential contacts.

Secondary prevention is an imperfect tool in the control of transmission of disease. It is often more expensive and less effective than primary prevention. In the long run, human health, happiness and useful longevity will be achieved at far less expense with less suffering through primary prevention than through secondary prevention.

Tertiary prevention

When the disease process has advanced beyond its early stages, it is still possible to accomplish prevention by what might be called “tertiary prevention”. It signifies intervention in the late pathogenesis phase. Tertiary prevention can be defined as “all measures available to reduce or limit impairments and disabilities, minimize suffering caused by existing departures from good health and to promote the patient’s adjustment to irremediable conditions”. For example, treatment, even if undertaken late in the natural history of disease may prevent sequelae and limit disability. When defect and disability are more or less stabilized, rehabilitation may play a preventable role. Modern rehabilitation includes psychosocial, vocational, and medical components based on team work from a variety of professions. Tertiary prevention extends the concept of prevention into fields of rehabilitation.

Modes of intervention

“Intervention” can be defined as any attempt to intervene or interrupt the usual sequence in the development of disease in man. This may be by the provision of treatment, education, help or social support. Five modes of intervention have been described which form a continuum corresponding to the natural history of any disease. These levels are related to agent, host and environment and are shown. They are:

1. Health promotion
2. Specific protection
3. Early diagnosis and treatment
4. Disability limitation
5. Rehabilitation

Health Promotion

Health promotion is “the process of enabling people to increase control over, and to improve health”. It is not directed against any particular disease, but is intended to strengthen the host through a variety of approaches (interventions). The well-known interventions in this area are:

1. health education
2. environmental modifications
3. nutritional interventions
4. lifestyle and behavioural changes

1. Health education: This is one of the most cost­ effective interventions. A large number of diseases could be prevented with little or no medical intervention if people were adequately informed about them and if they were encouraged to take necessary precautions in time. Recognizing this truth, the WHO’s constitution states that “the extension to all people of the benefits of medical, psychological and related knowledge is essential to the fullest attainment of health”. The targets for educational efforts may include the general public, patients, priority groups, health providers, community leaders and decision-makers.
2. Environmental modifications: A comprehensive approach to health promotion requires environmental modifications, such as provision of safe water; installation of sanitary latrines; control of insects and rodents; improvement of housing, etc. The history of medicine has shown that many infectious diseases have been successfully controlled in western countries through environmental modifications, even prior to the development of specific vaccines or chemotherapeutic drugs. Environmental interventions are non-clinical and do not involve the physician.
3.  Nutritional interventions: These comprise food distribution and nutrition improvement of vulnerable groups; child feeding programmes; food fortification; nutrition education, etc.
4. Lifestyle and behavioral changes: The conventional public health measures or interventions have not been successful in making inroads into lifestyle reforms. The action of prevention in this case, is one of individual and community responsibility for health the physician and in fact each health worker acting as an educator than a therapist. Health education is a basic element of all health activity. It is uppermost importance in changing the views, behavior and habits of people.  Since health promotion comprises a broad spectrum of activities, a well-conceived health promotion programme would first attempt to identify the “target groups” or at-risk individuals in a population and then direct more appropriate message to them. It involves “organizational, political, social and economic interventions designed to facilitate environmental and behavioral adaptations that will improve or protect health”.

Specific protection

To avoid disease altogether is the ideal but this is possible only in a limited number of cases. The following are some of the currently available interventions aimed at specific protection:

• immunization
• use of specific nutrients
• chemoprophylaxis
• protection against occupational hazards
• protection against accidents
• protection from carcinogens
• avoidance of allergens
• the control of specific hazards in the general environment, e.g., air pollution, noise control
• control of consumer product quality and safety of foods, drugs, cosmetics, etc.

Health protection: – The term “health protection” which is quite often used, is not synonymous with specific protection. Health protection is defined as “The provision of conditions for normal mental and physical functioning of the human being individually and in the group. It includes the promotion of health, the prevention of sickness and curative and restorative medicine in all its aspects”. In fact, health protection is conceived as an integral part of an overall community development programme, associated with activities such as literacy campaigns, education and food production. Thus health protection covers a much wider field of health activities than specific protection.

Early diagnosis and treatment

Early detection and treatment are the main interventions of disease control. The earlier a disease is diagnosed and treated the better it is from the point of view of prognosis and preventing the occurrence of further cases (secondary cases)or any long-term disability. Strictly speaking, early diagnosis and treatment cannot be called prevention because the disease has already commenced in the host. However, since early diagnosis and treatment intercepts the disease process, it has been included in the schema of prevention, in as much as the goal of prevention is “to oppose or intercept a cause to prevent or dissipate its effect.”

Early diagnosis and treatment though not as effective and economical as “primary prevention” may be critically important in reducing the high morbidity and mortality in certain diseases such as essential hypertension, cancer cervix and breast cancer. For many others such as tuberculosis, leprosy and STD, early diagnosis and treatment are the only effective mode of intervention. Early effective therapy has made it possible to shorten considerably the period of communicability and reduce the mortality from acute communicable diseases.

Disability limitation

When a patient report late in the pathogenesis phase, the mode of intervention is disability limitation. The objective of this intervention is to prevent or halt the transition of the disease process from impairment to handicap.

Concept of disability.

The sequence of events leading to disability and handicap have been stated as follows:

Disease → impairment → disability →handicap

The WHO has defined these terms as follows:

• Impairment: An impairment is defined as “any loss or abnormality of psychological, physiological or anatomical structure or function”, e.g., loss of foot, defective vision or mental retardation. An impairment may be visible or invisible, temporary or permanent, progressive or regressive. Further, one impairment may lead to the development of “secondary” impairments as in the case of leprosy where damage to nerves (primary impairment) may lead to plantar ulcers (secondary impairment).
• Disability: Because of an impairment, the affected person may be unable to carry out certain activities considered normal for his age, sex, etc. This inability to carry out certain activities is termed “disability”. A disability has been defined as “any restriction or lack of ability to perform an activity in the manner or within the range considered normal for a human being”.
• Handicap: As a result of disability, the person experiences certain disadvantages in life and is not able to discharge the obligations required of him and play the role expected of him in the society. This is termed “handicap”, and is defined as “a disadvantage for a given individual, resulting from an impairment or a disability, that limits or prevents the fulfilment of a role that is normal (depending on age, sex, and social and cultural factors) for that individual”.

Taking accidents as an example, the above terms can be explained further as follows:

• Accident. … . Disease (or disorder)
• Loss of foot …Impairment (extrinsic or intrinsic)
• Cannot walk … Disability (objectified)
• Unemployed …. Handicap (socialized)

The intervention in disability will often be social or environmental as well as medical. While impairment which is the earliest stage has a large medical component, disability and handicap which are later stages have large social and environmental components in terms of dependence and social cost.

Disability prevention

Another concept is “disability prevention”. It relates to all the levels of prevention:

• reducing the occurrence of impairment, viz. immunization against polio (primary prevention);
• disability limitation by appropriate treatment(secondary prevention); and,
• preventing the transition of disability into handicap (tertiary prevention).

The major causes of disabling impairments in the developing countries are communicable diseases, malnutrition, low quality of perinatal care and accidents. These are responsible for about 70% of cases of disability in developing countries. Primary prevention is the most effective way of dealing with the disability problem in developing countries.

5. Rehabilitation

Rehabilitation has been defined as “the combined and coordinated use of medical, social, educational and vocational measures for training and retraining the individual to the highest possible level of functional ability”. It includes all measures aimed at reducing the impact of disabling and handicapping conditions and at enabling the disabled and handicapped to achieve social integration. Social integration has been defined as the active participation of disabled and handicapped people in the mainstream of community life.

Rehabilitation medicine has emerged in recent years as amedical speciality.It involves disciplines such as physicalmedicineor physiotherapy, occupational therapy, speechtherapy, audiology, psychology, education, social work,vocational guidanceand placement services.

The followingareas of concern in rehabilitation have been identified:

1. Medical rehabilitation- restoration of function.
2. Vocational rehabilitation – restoration of the capacity to earn a livelihood.
3. Social rehabilitation – restoration of family and social relationships.
4. Psychological rehabilitation restoration of personal dignity and confidence

1. Medical rehabilitation

Medical rehabilitation does not stop at the level of treatment of illness in the ‘terminal phase’ but to see the patient be restored and retained to live and work at the best of his abilityin spite of his disability limitations. This process of rehabilitation must start very early along with the process of treatment.

The purpose of rehabilitation is to make productive people out of nonproductive people. Various examples of rehabilitation are:

• Provision of aid for crippled
• Reconstructive surgery to leprosy
• Graded exercise in neurological disorders like-polio

2. Vocational rehabilitation

When a productive man becomes non- productive on account of disability it is not only an economic loss but to the patient it amounts to loss of peace which pushes him into various psychological consequences, like frustration, loss of confidence etc. It is true that the physical disability on account of any disease produces loss of functional ability and thereby lessens the earning capacity. The physical rehabilitation by various rehabilitative measures improves the functional capacity of the individual and thereby the earning capacity of the individual is also increased. Hence, the purpose of vocational rehabilitation is to make a person to improve his earning capacity by improving his functional ability. Various measures are available for these types of rehabilitation such as-

• To change his job which is suitable for physical capacity
• To changehis life style in case of cardiac and tuberculosis patient
• Provision of certain aids that can increase his physical ability to meet his professional needs

3. Social rehabilitation

Even when a man is disabled, he has to perform a role of a member of the society. A man who is a father in a family incapacitated due to disability has to perform the role of a father to his son, as a husband to his wife, as a companion to his friend etc. The disability stands in the way of fulfilling his social role and consequently there is possibility of deterioration of relationship between the disabled and the members of the family and community in course of time.

Very often, a disabled person is not treated by the community like a normal person, which in turn produce Agony (extreme physical or mental suffering) in the mind of disabled. So, the members of the community are to be motivated as to how to treat the disabled person with sympathy and humanitarian touch and to build up confidence in his mind and as to how to perform his social role as much as he can. A set of activities aimed at rehabilitation and improving the functional capability of people and their inclusion in the society.

4. Psychological rehabilitation

It is well known fact that the disabled person is psychologically broken down resulting in frustration, agony etc. We have already seen the loss earning capacity and the incapability to fulfill the social functions aggravate the emotional conflicts of the disabled person. Hence, each disabled person is to be rehabilitated psychologically so as to bring him happiness. For this purpose, every psychologist must know:

• Mental makeup of the disabled
• The degree of emotional conflict buried in him.
• His nature of profession, functional ability, his aims and ambitions before his disability
• How best his ambitions and wishes can be fulfilled with the limitations of his functional incapacity.
• To motivate the patient to build will and confidence that will better his prospects.
• The various means available in the family, community to restore psychological needs etc.

The purpose of psychological rehabilitation is to restore emotional stability in order to enable him to lead a peaceful life.