Preventive medicine

Preventive medicine aims to prevent disease occurrence as well as disease progression and complications after disease onset. The five levels of preventive medicine target all stages of disease: primordial prevention (prevention of disease risk factors), primary prevention (prevention of specific diseases), secondary prevention (identification of early-stage disease, e.g., using screening tests), tertiary prevention (optimization of care for an established disease to limit progression and complications), and quaternary prevention (prevention of medical overuse). Such efforts may occur on a population level (e.g., through public health interventions) or an individual level (e.g., through routine health maintenance). Challenges to the implementation of preventive medicine include the “prevention paradox” and nonadherence. Health promotion can help individuals overcome these challenges and empower them to improve their health.

See also “Adult health maintenance,” “Adolescent health care,” and “Well-child visits.”

Public health interventions are actions and policies introduced by public health authorities to protect and improve the health of a population. Population-based practice focuses on the health concerns of entire populations and intervenes at the individual, community, and systemic levels. ^[1]

Health promotion is defined as efforts that empower individuals to improve their health. These may occur on an individual or population level. ^[2]

Population-level interventions ^[2][3]

• Optimizing health care access
• Expanding access to health insurance (e.g., government-funded health insurance, private health insurance)
• Addressing social aspects of health care (e.g., social justice in health care, health care disparities, social determinants of health)
• Promoting educational efforts and health in schools (e.g., Whole School, Whole Community, Whole Child)
• Mandatory reporting of factors that can impact the health and safety of others (e.g., reportable diseases, child abuse, conditions necessitating driving restrictions)
• Public health legislation (e.g., laws prohibiting smoking in certain spaces, Nutritional Facts label to promote healthy eating)
• Ensuring healthy environmental conditions (e.g., clean food and water)

Individual-level interventions ^[3][4]

• Regular office visits focused on preventive health and screening, i.e.:
  • Adult health maintenance
  • Adolescent health care
  • Well-child visit
• Promoting healthy behaviors and enabling behavioral change, e.g.:
  • Preventive counseling and education (e.g., counseling on safer sex, photoprotective measures, lifestyle modifications for ASCVD prevention)
  • Smoking cessation
  • Treatment of alcohol use disorder
• Routine vaccinations
• Family planning services
• Chronic disease management

• Definition: actions that aim to prevent the development of risk factors for disease ^[5][6]
• Target: entire population ^[6]
• Goal: encourage positive and discourage negative lifestyle habits ^[6]
• Strategies
  • Health promotion
  • Mass education
  • Legislation
• Examples
  • Programs on food safety and nutrition guidelines
  • Campaigns discouraging tobacco and drug use (e.g., smokefree air laws in public buildings)
  • Building bicycle lanes and sidewalks to promote physical activity

Primordial prevention aims to prevent risk factors from developing, whereas primary prevention targets existing risk factors to prevent the onset of a disease. ^[7]

• Definition: actions targeted at preventing specific diseases from occurring to decrease the incidence and, subsequently, the prevalence of those diseases
• Target: entire population or selected groups of individuals without disease who are at increased risk of disease
• Goal: decrease incidence and, in turn, prevalence of a specific disease
• Strategies
  • Health promotion (health interventions, lifestyle modifications)
  • Environmental modifications (e.g., work safety)
  • Specific protection interventions (immunizations, chemoprophylaxis, safety of drugs and food)
• Examples
  • Immunization
  • Lifestyle modification (e.g., smoking cessation to reduce lung cancer risk, exercise to reduce the risk of heart disease, dental care to reduce the risk of tooth loss)
  • Fortification of salt with iodine to prevent iodine deficiency
  • Fluoridation of toothpaste, water, and salt to reduce the risk of dental conditions
  • Fortification of food with folic acid to reduce the prevalence of neural tube defects ^[8]
  • Health legislation (e.g., seat belt laws, food safety standards, traffic laws)
  • Routine neonatal ophthalmic antibiotic prophylaxis to prevent neonatal gonococcal conjunctivitis
  • Postexposure prophylaxis
  • For further information, see:
    • “Adult health maintenance”
    • “Anticipatory guidance for children”
    • “Preventive health recommendations for adolescents”
    • “Prenatal patient education”

Primary prevention helps to Prevent disease.

• Definition: actions targeted at early detection of disease in asymptomatic individuals to promote timely intervention, preventing disease progression and/or improving the chance of treatment success ^[9][10]
• Target: individuals at risk for disease
• Goal: detect disease and initiate treatment early to improve the chance of treatment success
• Strategy: two-step process
  • Screening test to identify disease
  • Follow-up for disease management
• For further information on screening, see:
  • “Adult health maintenance screening recommendations”
  • “Adolescent health screening”
  • “Pediatric screening recommendations”
  • “Prenatal care”
  • “Preventive health care for transgender individuals”

Screening complements diagnostics, but it is not a substitute.

Secondary prevention helps Screen.

• Definition: actions taken to optimize the care of patients with an existing disease to improve well-being and prevent complications ^[11]
• Target: individuals with an established disease
• Goal: decrease morbidity and mortality by preventing disease progression and reducing the risk of relapse
• Strategies
  • Chronic disease management
  • Strategies to improve treatment adherence
• Examples
  • Adjuvant therapy to reduce the risk of cancer recurrence (e.g., tamoxifen in breast cancer)
  • Blood pressure management (e.g., antihypertensives) to reduce the risk of a cardiovascular event
  • Diabetes management (e.g., antidiabetic drugs, HbA_1c monitoring) to reduce the risk of chronic kidney disease and/or cardiovascular events
  • Measures to prevent recurrent myocardial infarction (e.g., low-dose aspirin)

Tertiary prevention helps Treat.

• Definition: actions taken to avoid medical interventions in which the harms may outweigh the benefits ^[12]
• Target: individuals with the potential to undergo unnecessary or inappropriate diagnostic and therapeutic interventions
• Goal: prevent medical overuse (i.e., overdiagnosis and overtreatment) and avoidable iatrogenesis ^[13]
• Strategies
  • Practicing evidence-based medicine
  • Using shared decision-making before initiating medical interventions
  • Educating health care providers and patients on potential harms of unnecessary interventions (e.g., through initiatives such as the Choosing Wisely campaign)
  • Avoidance of exploitation of medical conditions to sell products and/or procedures ^[14]
• Examples
  • Inappropriate investigations leading to overdiagnosis: the detection of disease that would never manifest clinically or result in death
    • Screening individuals outside of the recommended age range (e.g., cervical cancer screening in individuals > 65 years of age without risk factors). ^[15][16][17]
    • MRI for lower back pain of < 6 weeks duration or without red flag features ^[18]
    • Unnecessary examinations (e.g., routine pelvic examination before prescribing contraception) ^[19]
  • Unnecessary or excessive treatment (overtreatment)
    • Antibiotics for viral infections
    • Use of opioids in chronic noncancer pain ^[20]
    • Antibiotics for acute mild to moderate sinusitis, as this may lead to antibiotic resistance ^[21]
  • Avoidable iatrogenesis
    • Use of the combined hormonal contraception in patients with absolute contraindications (e.g., migraine with aura)
    • Continuation of antidiabetic drugs (e.g., sulfonylureas) despite patients experiencing adverse effects (e.g., multiple hypoglycemic events)

QUaternary prevention helps sQUeeze out unnecessary interventions.

• Definition ^[22][23]
  • A preventive measure that benefits a population as a whole will offer little benefit to each individual member of that population (population approach to prevention; primordial and primary prevention)
  • A preventive measure that benefits a group of individuals susceptible to a particular disease will offer little benefit to the population as a whole (high-risk approach to prevention; secondary and tertiary prevention).
  • The high-risk approach and the population approach to prevention are complementary, but preventive medicine should prioritize preventing the underlying causes of disease (primordial and primary prevention) over reducing the impact of disease after it occurs (secondary and tertiary prevention).
  • The prevention paradox may lead to the misconception that a measure that provides no immediate benefit to the individual, provides no benefit to the entire population and that a small risk involved in a measure (e.g., vaccination) outweighs the benefits of that measure.
    • Misconceptions derived from the prevention paradox may negatively affect epidemiological policy as well as adherence in the population.
    • Primordial and primary prevention require consistent, long-term education programs for health care professionals as well as the general population to be effective.
• Examples
  • While heavy drinking carries a greater risk than moderate drinking, moderate drinking has a greater negative impact on the general population because the number of moderate drinkers is greater than that of heavy drinkers.
  • Seatbelt laws have prevented many severe injuries, yet the overall risk of dying in an accident due to not wearing a seatbelt is still low.

• Definitions
  • Disease cluster: an unusual aggregation, real or perceived, of cases of a disease that are grouped together in time and space
  • Disease outbreak: the sudden occurrence of more cases of a disease than expected in a given area, population, and/or season
• Identifying outbreaks
  • Outbreaks are identified by health authorities through reports that may come from hospitals, laboratories, health care providers, and even the general population.
  • After receiving an initial report, health authorities decide on whether to investigate further.
• Investigating outbreaks
  • Field investigation involves identifying a potential disease outbreak, forming a hypothesis about its cause, gathering data to test the hypothesis, and finally, developing and implementing control and prevention measures.
  • Steps of the field investigation usually include:
    • Preparing for the investigation
      • Gathering information about the condition, area, and/or population of interest
      • Organizing a team and necessary supplies
    • Confirming the outbreak
    • Establishing a case definition
    • Finding cases and documenting details of each case
    • Developing a hypothesis about the cause of the outbreak
    • Analyzing the gathered data and evaluating the hypothesis
    • Comparing and reconciling with laboratory and/or environmental studies
    • Developing and implementing control and prevention measures
    • Initiating or maintaining surveillance.
    • Communicating the findings to the public

• The Whole School, Whole Community, Whole Child (WSCC) model is a student-centered framework developed by the CDC for addressing health in schools.
• WSCC consists of ten components:
  • Physical education and physical activity
    • Physical activity recommendations are outlined in the Comprehensive School Physical Activity Program, which consists of five components: physical education, physical activity during school, physical activity before and after school, staff involvement, and family and community engagement.
    • Physical education is an academic subject for all K-12 students, which helps to develop motor skills, knowledge, and behaviors for a healthy lifestyle.
  • Nutrition environment and services
    • Food provided to students must meet the Nutrition Standards for School Meals issued by the USDA.
    • Free drinking water must be available to all students throughout the day.
    • The National School Lunch and Breakfast Programs provide nutritious, low-cost or free meals to children each school day.
  • Health education: Integration of health education into the curriculum involves addressing topics such as nutrition, mental health, sexual health, violence prevention, and the use of alcohol, tobacco, and other substances in a variety of subjects and educational settings.
  • Social and emotional climate: A positive emotional climate is essential for proper child development and should be maintained in all aspects of school functioning.
  • Physical environment: School buildings and surrounding environment should be safe from any health threat (e.g., traffic, crime, construction, improper ventilation).
  • Health services: Services from qualified health professionals (e.g., nurses, physicians, physician assistants) should be available to all students.
  • Counseling, psychological, and social services: prevention and intervention to support the mental, behavioral, and social health of students (i.e., with certified school counselors, school psychologists, and school social workers)
  • Employee wellness: School employees should have access to programs, policies, and benefits that promote their health and well-being.
  • Community involvement: partnerships with local groups, organizations, and businesses to encourage students' civic engagement and to share school resources (e.g., school-based health centers and sports facilities) with the community
  • Family engagement: continuous involvement of students' families in educational activities and development