What does "cumulative incidence" measure?

Cumulative incidence measures the proportion of a population that becomes diseased over a specified period of time. It is a key metric in epidemiology used to understand the risk of developing a disease within a defined time frame. By analyzing the number of new cases of a disease that occur in a population at risk during a certain period, this measure offers valuable insight into the dynamics of disease spread and occurrence.

In calculating cumulative incidence, researchers typically focus on an at-risk population, ensuring that individuals who already have the disease are excluded from the numerator. This allows for a clearer picture of how many new cases appear as a fraction of those who could potentially develop the condition. It provides critical information for public health officials and policymakers in understanding health trends and planning interventions effectively.

Understanding cumulative incidence is essential for evaluating outbreaks, screening programs, and the general burden of disease within populations, thus making it a fundamental concept in public health.