Clinical Research Glossary

incidence incidence


Number of new cases or events during a period of time.

Example of incidence in a sentence

The incidence rate tells us how many new cases of a specific disease or condition develop during a certain period of time.

More Info

Measuring the incidence is a way to keep track of how many new cases or events happen in a population at risk during a given time period.

The incidence is generally reported as a rate.

For example, in a study with 10 participants, if 3 people report headaches after taking the study medication and 7 do not, the incidence of headaches is 30% (3/10 = .3 or 30%)

Other info to think about when joining a study

You might see the word “incidence” used to describe the frequency of a disease or condition.

The word can also be used to describe the expected or actual number of adverse events in a study.

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