Certification Board of Infection Control and Epidemiology (CBIC) Practice Exam 2025 – The All-in-One Guide for Exam Success

Incidence is a measure used in epidemiology that reflects the frequency at which new cases of a disease occur in a population over a specific period of time. The correct calculation of incidence involves identifying the number of new cases that arise within the population at risk during a defined time frame, then dividing that number by the total population that is at risk during that same time period. This emphasis on new cases allows public health officials to understand the dynamics of disease spread and the effectiveness of interventions.

This approach is critical because it focuses exclusively on new cases rather than all cases, which helps in understanding trends and developing strategies for prevention and control. It excludes individuals who already have the disease from the population at risk because they are not at risk of developing the condition anew.

In summary, the calculation of incidence as the number of new cases divided by the number of persons at risk is vital for assessing public health outcomes and allocating resources effectively.