Word

incidence

noun C1

/ˈɪn.sɪ.dəns/

Meanings

noun

the rate or number of new cases of something occurring in a population during a particular period

noun

the frequency with which something happens

Definition

Incidence is how often something happens, especially the rate at which new cases occur in a population over a period of time.

Incidence refers to the number or rate of new occurrences of something within a specific group and time period. It is often used in public health to describe how many new cases of a disease appear. More generally, it can mean how frequently an event happens. It is different from prevalence, which counts all existing cases at a given time.

Examples

The report links the rising incidence of heat-related illness to longer, more intense summer heatwaves.
I tracked the incidence of late deliveries over three months to see whether our new routing system actually helped.
They noted a lower incidence of equipment failure after they introduced stricter maintenance checks.
She questioned whether the apparent incidence of plagiarism reflected better detection rather than worse student behavior.

Common mistake

Learners often confuse incidence (new cases over a period) with prevalence (all existing cases at a point in time).