Two assumptions inherent in epidemiologic studies include...

• A. Diseases are randomly distributed in populations.
• B. Diseases have no identifiable causes.
• C. Diseases are not randomly distributed, and have specific causes that can be identified, prevented, and treated.
• D. Diseases are solely caused by genetics.

Answer: (C)

In epidemiology, diseases are viewed as not being randomly scattered but rather following patterns that reveal underlying factors. This means there are specific, identifiable causes or risk factors that influence who gets a disease and why. Because these factors can be measured and studied, they can often be targeted to prevent illness or to reduce its impact, and they can inform treatment and public health actions. That’s why the best answer describes diseases as not randomly distributed and having identifiable causes that can be addressed through prevention and treatment.

The other ideas clash with this practice: imagining random distribution would erase meaningful patterns and prevent finding causes; saying there are no identifiable causes contradicts the whole goal of etiologic research; and attributing diseases solely to genetics ignores the multifactorial nature of most conditions, where environment, behavior, and social factors, often in combination with genetics, shape risk.