What term refers to the proportion of a population that has a disorder at a given time?

• A. Prevalence
• B. Incidence
• C. Prognosis
• D. Etiology

Answer: (A)

This item is about measuring how common a disorder is in a population at a specific moment. The term to describe that is prevalence—the proportion of people who have the disorder at that time. It can refer to a single point in time (point prevalence) or to a period, but in either case it counts all existing cases, not just new ones.

Incidence, by contrast, refers to new cases that develop during a defined time period. Prognosis is about the likely course or outcome for someone who has the disorder. Etiology concerns the cause or origin of the disorder.

So, the correct term for the proportion of a population that has a disorder at a given time is prevalence.