Preventive Interventions

Preventive interventions are actions that prevent a disease and reduce the incidence of new cases, including education, vaccines, nutritional interventions, maternal and neonatal interventions, behavioral interventions, and environmental interventions.

Vaccines

• Non-infectious antigens given to provoke an immune response that conveys protection against infection by a specific pathogen
• Often the most cost-effective interventions
• Employed as part of public health programs

Nutritional interventions

• Provide appropriate nutrition to prevent health problems related to malnutrition Malnutrition Malnutrition is a clinical state caused by an imbalance or deficiency of calories and/or micronutrients and macronutrients. The 2 main manifestations of acute severe malnutrition are marasmus (total caloric insufficiency) and kwashiorkor (protein malnutrition with characteristic edema). Malnutrition in children in resource-limited countries and/or nutrient deficiencies
• Applicable to all age groups (fetal development to adults)
• Often ongoing and long term
• Can target whole populations or specific subgroups 

Maternal and neonatal interventions

• Tests and care applied before/during pregnancy Pregnancy Pregnancy is the time period between fertilization of an oocyte and delivery of a fetus approximately 9 months later. The 1st sign of pregnancy is typically a missed menstrual period, after which, pregnancy should be confirmed clinically based on a positive β-hCG test (typically a qualitative urine test) and pelvic ultrasound. Pregnancy: Diagnosis, Maternal Physiology, and Routine Care, antepartum, and postpartum to prevent disease in both mother and child
• Examples:
  • Family planning 
  • Antenatal visits and routine screening tests
  • Antenatal monitoring (e.g., ultrasound)
  • Treatment of gestational infections
  • Nutritional recommendations and supplements
  • Access to adequate care during delivery

Educational and behavioral interventions

• Attempts to change behaviors linked to disease, often through widespread community education programs (e.g., educational campaigns, public awareness efforts, public service announcements)
• Efficacy dependent on individual willingness and effort
• Often must be implemented for years to demonstrate results

Environmental interventions

• Alterations to the environment of a population to reduce the risk of infection or disease
• Alterations often widespread, involving large-scale, costly changes to public spaces
• Success requires significant lifestyle changes and the co-operation of multiple individuals.
• Examples: 
  • Infrastructure changes (e.g., construction of proper sewage and clean water supplies)
  • Vector control (e.g., reduction of habitats and breeding sites) 
  • Pharmacological prophylaxis (e.g., antimalarial medication in endemic zones)

Therapeutic Interventions

Therapeutic interventions alleviate or prevent mortality (reduce case fatality rate) and morbidity of a disease once established, including the management of infectious disease, surgical and radiation treatment, diagnostics to guide therapy, and control of chronic diseases.

Management of infectious disease

• Use of pharmacologic agents that seek to kill or inhibit the replication of pathogens to prevent their spread and reduce associated mortality and morbidity
• Studies of these agents often involve:
  • Case detection: the ability to accurately diagnose and identify new cases 
  • Case holding: the ability to regularly follow and treat cases over a sufficient period of time to eliminate the pathogen

Surgical and radiation management

• Direct surgical or radiation interventions to reduce morbidity and mortality of disease 
• Often seen as part of randomized control trials (RCTs)

Diagnostics to guide therapy

• Application of diagnostic tests Diagnostic tests Diagnostic tests are important aspects in making a diagnosis. Some of the most important epidemiological values of diagnostic tests include sensitivity and specificity, false positives and false negatives, positive and negative predictive values, likelihood ratios, and pre-test and post-test probabilities. Epidemiological Values of Diagnostic Tests to accurately identify new cases and assess the effectiveness of management 
• Studies are performed to assess specificity and sensitivity of diagnostic tests Diagnostic tests Diagnostic tests are important aspects in making a diagnosis. Some of the most important epidemiological values of diagnostic tests include sensitivity and specificity, false positives and false negatives, positive and negative predictive values, likelihood ratios, and pre-test and post-test probabilities. Epidemiological Values of Diagnostic Tests to increase diagnostic accuracy, leading to a reduction in disease impact.

Control of chronic diseases

• Clinical care in addition to management:
  • Screening to identify new cases, clinical assessment of each stage of disease
  • Monitoring and management of complications of disease 
• Studies often require years to decades to evaluate.

Other Interventions

Other interventions also affect disease burdens, including governmental and healthcare system changes.

Governmental changes

• Widespread changes in policy, legislation, or taxes that seek to change public behavior that leads to or exacerbates disease 
• Assessment studies are difficult because implementation is often nationwide, and it is difficult to find a control group.

Healthcare system changes

• Include changes in health sector training, healthcare organization, healthcare education, financing, and decentralization of care 
• Studies often involve a “step approach,” where phased implementations are evaluated over time to assess efficacy.