Which prevalence measure represents the proportion of people alive on a given day who previously had a diagnosis or the disease, regardless of how long ago the diagnosis was, or if the patient is still under treatment or is considered cured?

• A. Complete prevalence
• B. Limited-duration prevalence
• C. Point prevalence
• D. Period prevalence

Answer: (A)

This question tests how prevalence measures differ in what they count over time. The scenario described—proportion of people alive on a given day who have ever been diagnosed with the disease, regardless of how long ago or current treatment status—maps to complete prevalence. This measure captures all individuals who have ever had the disease and are still alive at the chosen date, whether they are still receiving treatment, in remission, or cured.

Point prevalence would only include people who currently have the disease on that exact day. Period prevalence covers anyone who had the disease at any time during a specified interval, emphasizing disease presence during the period rather than simply ever having been diagnosed by the chosen date. Limited-duration prevalence narrows to those diagnosed within a defined recent window. So, the described concept aligns with complete prevalence.