prevalence
PREH-vuh-lents
/ˈprɛvələns/
The fact or condition of being prevalent; commonness. In medicine, the total number of cases of a disease in a population at a given time.
Prevalence measures how much of a disease is 'out there' right now, whereas 'incidence' measures new cases appearing.
The story behind the word. 'Prevalence' comes from the Latin 'praevalere', which means 'to be very strong' or 'to have superior power.' In a health context, if a disease has high prevalence, it means it has a 'strong' presence in the population.
Word relationships
- commonness: A simpler term for how often something occurs.
- ubiquity: The state of being everywhere at once, which is stronger than prevalence.
- rarity: The state of being very uncommon.
- scarcity: A lack of something, rather than its commonness.
Commonly confused with
- incidence: Incidence is the rate of new cases; prevalence is the total number of existing cases.
Word family
- prevalent (adjective): Widespread in a particular area or at a particular time.
- prevail (verb): To be widespread or current.
Collocations
- high prevalence
- prevalence rate
- estimated prevalence
- increasing prevalence
Example sentences
- "The prevalence of obesity has nearly tripled worldwide since 1975." Public health report. (World Health Organization)
- "Researchers are concerned about the prevalence of sedentary behavior among teenagers." Sociological study.
Memory hook
'Pre' (Before) + 'Valence' (Value/Strength) = The strength of a condition before our eyes in a population. Prevalence: How present it is.
When not to use
Don't use it when you mean 'importance' or 'strength' in a non-statistical way.
Fun facts
- Prevalence is often expressed as a percentage of the population (e.g., a 12% prevalence of asthma).
Related words
Explore more words
epidemiology, chronic, cohort, ubiquitous, omnipresent, mortality
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