Advanced Dental Admission Test (ADAT)

How is incidence defined in terms of disease occurrence?

1. Number of existing cases at a single point in time

2. Proportion of the population with a specific disease

3. Number of new cases diagnosed over a certain period

4. Rate of recovery from the disease

The correct answer is: Number of new cases diagnosed over a certain period

Incidence is defined as the number of new cases of a disease that occur within a specified time frame in a given population at risk. This measurement looks specifically at how frequently new diagnoses are made, providing insight into the dynamics of disease spread and the effectiveness of public health interventions over time. By focusing on new cases, incidence captures the temporality of disease development, which is crucial for understanding trends and making predictions about future case numbers. It is distinct from prevalence, which refers to existing cases rather than new ones, and from recovery rates, which look at how many people recover from the disease rather than how many new cases arise. Understanding incidence helps health professionals identify at-risk populations and monitor the impact of preventive measures or outbreaks.