Prevalence Definition — NDEB AFK MCQ
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Correct answer: C — The total number of existing cases (old and new) of a disease in a population at a specific point in time
Prevalence is the proportion of a defined population that has a disease at a specific point in time (point prevalence) or during a specified period (period prevalence). It includes both new and pre-existing cases. Prevalence = number of existing cases / total population. Unlike incidence (which measures new cases only), prevalence is influenced by both the rate of new cases (incidence) and the duration of the disease. Chronic diseases with long duration have higher prevalence relative to incidence.
Reference: Burt & Eklund – Dentistry, Dental Practice, and the Community, 7th ed., 2005