Prevention And Screening

Prevention

Definition

Prevention is defined as "activity to decrease or eliminate or lessen the onset, causes, consequences, or recurrence of illness" by the Australian N National Public Health Partnership. Preventive action involves avoiding risk factors before a disease develops.

Levels of Prevention

The concept of prevention has become broad based. It has been define in terms of four levels.

• Primordial Prevention,
• Primary Prevention,
• Secondary Prevention,
• Tertiary Prevention.

Primordial Prevention: Prevention of the emergence or development of risk factors that causing disease. The main intervention in primordial prevention is through individual and mass education. For example, adult health problems ( e, g : obesity, hypertension) have their early origins in childhood, because this is the time when lifestyles is formed like smoking, eating patterns, physical exercise. In primordial prevention, efforts are directed towards discouraging children from adopting harmful lifestyles.

Primary Prevention: Action taken before onset of disease, which remove the possibility t disease will ever occur. Primary prevention is achieved by health promotion and well-be quality of life of people or by specific protection. Primary prevention services and activities include:

• Immunization,
• Provision of information on behavioral and medical health risks, and measures to reduce risks at the individual and population levels;
• Inclusion of disease prevention programme at primary and specialized health care such as access to preventive services (eg. counseling) level,
• Nutritional and food supplementation,
• Dental hygiene education and oral health services.

Secondary Prevention: Action that prevent the progress of disease at its developing stage and prevents its complications. The specific intervention are early diagnosis and treatment (screening test, case finding) Secondary prevention includes activities such as:

• Provision of maternal and child health programmes, including screening and prevention of congenital malformations; and
• Population-based screening programmes for early detection of diseases;

Tertiary Prevention: It is defined as "all measures available to reduce or limit impairment a vision of chemo-prophylactic agents to control risk factors (e.g., hypertension) disabilities and to improve function, minimise impact, and delay complications". For example treatment even if undertaken late in the natural history of disease may prevent sequelae limit disability. Tertiary prevention can be done by disability limitation and rehabilitation. 

Screening

Screening is described as "the fast use of tests, examinations, or other procedures in seemingly healthy persons to seek for identified illness or deficiency."

One of the most important aspects of prevention is the proactive search for disease among those who appear to be healthy.

Aims and Objectives

• The basic purpose is to sort out from a large group of apparently healthy persons those likely to have the disease or at increased risk of the disease under study.
• Screening is carried out for early diagnosis and subsequent treatment.

Uses of Screening

• Case Detection: It is defined as the presumptive identification of unrecognized disease, which does not arise from patient's request, e.g; neonatal screening. In other words, people are screened primarily for their own benefit. Specific disease such as cervical cancer, breast cancer, diabetes mellitus, iron deficiency anemia.
• Control of Disease: People are examined for the benefit of others eg screening of immigrants from infectious diseases such as tuberculosis and syphilis to protect the home population and screening for streptococcal infection to prevent rheumatic fever.
• Research Purposes: Sometimes screening can be done for research purpose. For examples, many chronic disease whose natural history is not fully known (eg, cancer, hypertension)
• Educational Opportunities: Screening provide opportunities for creating public awareness and for educating health professionals. foreg; screening about hypertension and teach about how to minimize about the risk factors.

Types of Screening

There are three types of screening have been described:

• Mass Screening.
• High risk or selective screening.
• Multiphase Screening.

Mass Screening: It means screening of whole population for eg: all adults. It is offered to all, irrespective of the particular risk individual may run of contracting the disease in question (eg: tuberculosis) Mass screening received support in the past but it is criticized as it is not a useful preventive measure unless it is backed up by suitable treatment that will reduce the duration of illness or alter its final outcome.

High risk or Selective Screening: High risk screening is the effective, most productive if applied selectively to the high risk groups, the groups defined on the basis of epidemiological research. The concept of screening for disease to screening for "risk factors" as these factors can cause the development of actual disease. for example: elevated serum cholesterol is associated with a high risk of developing coronary heart disease. In this way, preventive measures can be applied before the disease occurs, beside effectiveness, economical use of resources will occur if the screening tests are selectively applied to individuals in high risk groups.

Multiphasic Screening: It has been defined as the application of two or more screening tests in combination to a large number of people at one time than to carry out separate screening tests for single diseases. The procedure may also include a health questionnaire, clinical examination, measurements and investigations.