Incidence or Incidents?

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What Is the Difference between "Incidence" and "Incidents"?

"Incidence" and "incidents" are easy to confuse because they sound identical (i.e., they are perfect homonyms). However, their meanings are very different.

• "Incidence" is the number of new cases of disease (e.g., a coronavirus, COVID-19, the flu, the measles) or injury in a population over a specified period of time. (More below)
• An "incident" is an event. The plural is "incidents."

Incidence

The noun "incidence" was rare before the COVID-19 pandemic. "Incidence" is a technical word used in the field disease control. It refers to the chance of developing a new condition (usually a disease) within a specified time period.

Example sentences with "incidence":

• The chart 'Incidence of Flu by Area' shows the number of people with coronavirus and coronavirus symptoms who visited their doctor last week.
• They suffer a higher incidence of measles as they did not invest in health-care systems to deliver vaccinations effectively.

There are two main measure of incidence:

• Incidence Risk. Incidence risk is the proportion of individuals in a population (initially free of disease) who develop the disease within a specified time.
• Incidence Rate. Incidence rate is the frequency of new cases of disease in a population.

Read more about the measures of disease on "Health Knowledge."

Incidents

The word "incidents" is the plural of "incident," which means an occurrence or an event.

Example sentences with "incidents":

• There is no evidence to link the two incidents at this time.
• The police are investigating two incidents of someone shooting into occupied homes.

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