Preventive Medicine and Public Health Flashcards

Herd immunity is achieved when what proportion of a population is immune, preventing sustained transmission of an infectious disease?

Answer: A threshold proportion sufficient to interrupt transmission chains (varies by disease)

Herd immunity thresholds vary by pathogen transmissibility (R0); measles requires ~95% immunity while polio requires ~80–85%.

Which dietary pattern is most strongly associated with reduced cardiovascular disease risk in evidence-based medicine?

Answer: Mediterranean diet (rich in fruits, vegetables, whole grains, olive oil, fish)

The Mediterranean diet has the strongest evidence base for cardiovascular risk reduction, including the landmark PREDIMED trial showing reduced major cardiac events.

Which occupational exposure is most strongly linked to mesothelioma?

Answer: Asbestos

Asbestos exposure is the primary cause of mesothelioma, a malignant tumor of the pleura, peritoneum, or pericardium, with a latency period of 20–50 years.

The number needed to treat (NNT) is calculated as:

Answer: 1 / absolute risk reduction (ARR)

NNT = 1/ARR; it tells clinicians how many patients must receive treatment for one additional patient to benefit compared to the control condition.

USPSTF recommends screening for lung cancer with low-dose CT (LDCT) in adults with what criteria?

Answer: Ages 50–80, 20 pack-year smoking history, current smoker or quit within 15 years

The 2021 USPSTF recommendation expanded lung cancer screening to ages 50–80 with ≥20 pack-years who currently smoke or quit within 15 years.

Which preventive intervention has the greatest impact on reducing infant mortality in the US?

Answer: Safe sleep practices (back sleeping, firm mattress, no bed-sharing)

The 'Back to Sleep' campaign (now Safe to Sleep) dramatically reduced SIDS deaths by promoting supine infant sleeping position.