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.
- 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
- Provide appropriate nutrition to prevent health problems related to malnutrition 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, antepartum, and postpartum to prevent disease in both mother and child
- 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
- 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.
- 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 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 to accurately identify new cases and assess the effectiveness of management
- Studies are performed to assess specificity and sensitivity 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 also affect disease burdens, including governmental and healthcare system 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.
- Smith, P., Morrow, R. & Ross, D. (2015). Field trials of health interventions: a toolbox. Oxford University Press.