Which term describes the risk of disease occurrence in a defined population?

The term that describes the risk of disease occurrence in a defined population is incidence. Incidence refers specifically to the number of new cases of a disease that develop within a specified period of time, typically expressed per a certain number of individuals in the population, such as per 1,000 or 100,000 people. This measure is critical for understanding how quickly a disease is spreading and helps public health officials gauge the risk of developing the disease within that population.

In contrast, prevalence measures the total number of existing cases (both new and old) of a disease in a given population at a particular time, providing insight into how widespread the disease is, rather than focusing on new occurrences. Endemic refers to the constant presence of a disease within a specific geographic area or population, while epidemic indicates a sudden increase in the number of cases of a disease above what is normally expected in that area or population. Each of these terms serves distinct purposes in the field of epidemiology, but incidence specifically highlights the risk associated with new disease cases.