Health Promotion, Population Health and Public Health
What this domain tests
Health promotion, population health and public health test prevention at the individual and community level: levels of prevention, screening criteria, immunization, harm reduction, health equity, social determinants, outbreak investigation, notifiable diseases, and travel health.
Core rules
- Primary prevention prevents disease before it occurs (immunization, smoking prevention); secondary prevention detects early disease (screening); tertiary prevention limits complications (rehabilitation, adherence).
- Screening is appropriate when the condition is important, has a detectable early stage, has an accepted treatment, and the test is acceptable, safe and cost-effective; false positives and overdiagnosis are real harms.
- Sensitivity = true positives / all with disease; specificity = true negatives / all without disease. Positive predictive value depends heavily on prevalence.
- Herd immunity protects those who cannot be vaccinated; vaccine contraindications include severe allergic reaction to a component and some live vaccines in pregnancy or immunocompromise.
- Harm reduction accepts that some people use substances and aims to reduce harm (naloxone, sterile supplies, supervised consumption) without requiring abstinence.
- Health equity means removing unfair, avoidable barriers; social determinants include income, housing, food security, education and racism.
Worked example
A 52-year-old with no family history and no symptoms asks about colon cancer screening. He is average risk. Offer FIT every 2 years (or colonoscopy every 10 years, depending on jurisdiction and preference). Explain that FIT is non-invasive but not perfect; a positive FIT requires colonoscopy. If his father had colorectal cancer at 55, he would be at increased risk and screening would start earlier and use colonoscopy. The reasoning is risk stratification first, then test choice, then follow-up.
Traps
Do not screen low-risk asymptomatic people with tests that have poor positive predictive value; do not confuse sensitivity with positive predictive value; do not recommend live vaccines in pregnancy or severe immunocompromise; do not moralize about substance use; do not ignore cost, transportation or language barriers; do not forget notifiable disease reporting.