Learning Objective: After studying this topic, medical students should be able to differentiate primary, secondary, and tertiary prevention, provide clinical examples for each level, and explain how these strategies reduce morbidity and mortality in populations.
Goals of Prevention
- Promote health
- Preserve health
- Restore health when impaired
- Minimize suffering and distress
These goals aim to reduce both morbidity and mortality in populations and individuals.
Primary Prevention
Definition: Interventions that prevent the onset of disease by promoting healthy behaviors and reducing exposure to risk factors or environmental hazards.
Key Features:
- Focuses on healthy individuals or communities
- Aims to decrease disease incidence
Examples:
| Intervention | Level / Purpose |
|---|---|
| Exercise programs in schools | Promotes a healthy lifestyle |
| Healthy food programs | Reduces obesity and cardiovascular risk |
| Wearing a mask to prevent meningococcal exposure | Prevents infection before disease onset |
Secondary Prevention
Definition: Interventions that detect and treat disease early, often before symptoms appear, to prevent progression.
Key Features:
- Focuses on early detection of asymptomatic or mild disease
- Permits timely intervention or curative treatment
- Aims to reduce disease prevalence
Examples:
| Screening / Intervention | Target Population |
|---|---|
| Annual colonoscopy | Patients age > 65 |
| HIV testing after a needle stick injury | Health care workers |
| Blood pressure screening | Adults ≥ 40 years |
Tertiary Prevention
Definition: Interventions that reduce long-term impairments or disabilities, prevent recurrence, and slow disease progression.
Key Features:
- Focuses on patients with established disease or injury
- Aims to improve the quality of life and reduce complications
Examples:
| Intervention | Target Population / Purpose |
|---|---|
| Physical therapy | Spinal injury patients – improve function |
| Daily low-dose aspirin | Post-myocardial infarction – prevent recurrence |
| Prosthetic limb replacement | Wounded war veterans – improve mobility, reduce complications |
Summary Table of Prevention Levels
| Prevention Type | Goal | Population | Effect | Examples |
|---|---|---|---|---|
| Primary | Prevent disease | Healthy individuals | ↓ Incidence | Exercise programs, a healthy diet, and masks |
| Secondary | Early detection & treatment | At-risk / early disease | ↓ Prevalence | Colonoscopy, HIV testing, BP screening |
| Tertiary | Reduce complications & disability | Patients with the disease | Prevent recurrence / slow progression | Physical therapy, aspirin, prosthetics |
