- Disease prevention is a procedure through which individuals, those with risk factors for a disease or without the risk factors, are treated in order to prevent a disease from occurring.
- Treatment normally begins either before signs and symptoms of the disease occur, or shortly thereafter.
- Prevention includes a wide range of activities — known as “interventions” — aimed at reducing risks or threats to health.
- It can include patient education, lifestyle modification, and drugs.
Levels of Prevention
Prevention can be considered on a number of levels:
- It seeks to prevent at a very early stage, often before the risk factor is present in the particular context, the activities which encourage the emergence of lifestyles, behaviors and exposure patterns that contribute to increased risk of disease.
- For example, a child seeing their parents smoke cigarettes may wrongly consider this a good lifestyle choice for later in life: advising parents to quit smoking in such circumstances can be considered primordial prevention.
- Control aimed at reducing the incidence of infectious disease or their risk factors can be considered as primary prevention of infectious disease.
- Primary prevention protects health through individual and community-wide measures, including such actions as maintaining good nutritional status, keeping physically fit, immunizing against infectious diseases, providing safe water, and ensuring the proper disposal of feces.
- Control aimed at reducing the prevalence by shortening the duration of infectious disease can be considered as secondary prevention of infectious disease.
- Secondary prevention corrects departures from good health through individual and community-wide measures, including such actions as screening that result in early detection of disease, prompt antibiotic treatment, and ensuring adequate nutrition.
- It should be noted that such control efforts in secondary prevention in a group of infected individuals may also result in primary prevention in uninfected people.
- For example, prompt and specific drug therapy for tuberculosis patients resulting in sputum conversion to culture-negative status renders them no longer a source of infection to others and treatment of HIV-positive pregnant women reduces transmission of HIV to their newborns.
- Control aimed at reducing or even eliminating long-term impairments of infectious disease can be considered as tertiary prevention of infectious disease.
- Tertiary prevention reduces or eliminates disabilities, minimizes suffering, and promotes adjustment to permanent disabilities through such actions as providing orthopedic appliances and its associated rehabilitation for victims of poliomyelitis, counseling and vocational training, and prevention of opportunistic infections.
- For example, the prevention of opportunistic infections in HIV infection can be considered as tertiary prevention.
Approaches to Disease Prevention
Targeting populations versus high-risk only groups
- There are two approaches to prevention – targeting a whole population whether they are exposed to risk factors or not, or tackling only those identified as being high risk.
- There are pros and cons to each approach.
- High-risk groups can be identified through screening, genetic testing, analytical studies linking risk factors and disease and ecological studies to identify groups.
- Maybe more cost-effective than population-wide approaches
- Those who are identified as being high risk may be more motivated to change their behavior than the whole of society
- Easier for health professionals to promote change on an individual basis
- Individuals are usually aware of their exposure to adverse risk, whereas in society not everyone will have been exposed
- Society prefers focusing on individuals to change rather than a whole population
- Can be expensive to identify and treat those at increased risk
- Fails to address public health problems arising from small but widespread risks that may be substantial
- Ignores the point that a large number of people exposed to a small risk may generate more cases than a small number of people exposed to a large risk
- Tends to medicalize prevention
- Strategies for the individual tend to be either palliative or temporary
- Does not focus on what influences behavior
- Does not tend to predict an individual’s change in risk
- May have a little overall impact on the control of disease
- Recognizes that society influences individual behavior
- Risk reduction can be achieved at population rather than individual level
- In situations where there is a dose-response relationship in terms of risk and exposure, shifting the entire population distribution towards lower levels of exposure is effective.
- Is less effective in situations where there is not a dose-response relationship in terms of risk and exposure
Rose hypothesis: The prevention paradox
- Since diseases are rare, most individuals who adopt a behavior designed to lower their risk of disease will not benefit directly, although a few individuals may benefit enormously.
- For example, anyone person’s decision to lose weight may only have a small impact on that person’s risk of disease in the near future, but if many people each lose a little weight, this may have a substantial impact on the community’s obesity-related disorders.
- Although individuals with high-risk factors may benefit from interventions specifically targeted at them, the effect on the overall incidence of the disease will be limited in the absence of a population-oriented intervention.
- Whilst the high-risk approach seemingly has many more disadvantages compared to the population approach, the prevention paradox reduces the effectiveness of the population approach, therefore a combination of population and high-risk approaches is usually most effective.
Key Components of Prevention
1. Awareness and Education
- Inform and educate decision-makers, public health practitioners, health care providers, and individuals about science-based health prevention approaches that will have the greatest benefit and impact on public health.
- Provide information on the effectiveness of interventions to inform policies.
- Educate workers both in and out of the health field who may have daily contact with people at high risk for disease and injury. These individuals can encourage healthy behaviors, screen for certain health risks, and contribute to the education of the community.
- Provide the public with health education information.
- Work with the media to highlight public health issues.
- Establish programs to proactively distribute information to targeted groups—those at high risk for disease or injury.
- Identify and support public health research agenda at the national level. This research would address knowledge gaps in suspected and emerging links between exposure to harmful agents and health outcomes.
3. Surveillance at all levels
- Monitor risk areas or situations and determine the prevalence of agent-linked health outcomes.
- Identify national, state, or community health issues; develop measures to track those issues; and implement widespread surveillance to help identify relationships between hazards and health concerns.
4. Hazard evaluation at the national, state, and local levels
- Implement hazard assessments as needed. Respond to high-risk situations, identify and quantify hazardous agents, and facilitate exposure reduction.
- Improvement of the public health system at the national, state, and local levels
5. Proactive behavior by individuals
- Make healthy lifestyle choices, choose environmentally-friendly products and services, and conscientiously try to minimize the harmful impact of yourself and your family.
- Become informed about the issues, and be proactive in prevention initiatives promoting health and preventing illness and disease.
- Gordis, L. (2014). Epidemiology (Fifth edition.). Philadelphia, PA: Elsevier Saunders.
- White, F., Stallones, L., & Last, J. M. (2013). Global public health: Ecological foundations. New York, NY: Oxford University Press.
- Park, K. (n.d.). Park’s textbook of preventive and social medicine.
- Hennekens CH, Buring JE. Epidemiology in Medicine, Lippincott Williams & Wilkins, 1987.