What is prevalence?

  • (noun): (epidemiology) the ratio (for a given time period) of the number of occurrences of a disease or event to the number of units at risk in the population.
    See also — Additional definitions below


In epidemiology, the prevalence or prevalence proportion is the proportion of a population found to have a condition (typically a disease or a risk factor such as smoking or seat-belt use). It is arrived at by comparing the number of people found to have the condition with the total number of people studied, and is expressed as a fraction, as a percentage or as the number of cases per 10,000 or 100,000 people. "Point prevalence" is the proportion of a population that has the condition at a specific point in time. "Period prevalence" is the proportion of a population that has the condition at some time during a given period ("12-month prevalence", etc), and includes people who already have the condition at the start of the study period as well as those who acquire it during that period. "Lifetime prevalence" (LTP) is the proportion of a population that at some point in their life (up to the time of assessment) have experienced the condition.

Read more about Prevalence.

Some articles on prevalence:

Prevalence - Limitations
... rates for disorders and conditions with a relatively low population prevalence or base-rate ... the receiver operating characteristic curve), a condition with a relatively low prevalence or base-rate is bound to yield high false positive rates, which exceed ...
System Prevalence
... System prevalence is a simple software architectural pattern that combines system images (snapshots) and transaction journaling to provide speed, performance ... of the term and generic, publicly available implementation of a system prevalence layer was Prevayler, written for Java by Klaus Wuestefeld in 2001 ...
Chronic Prostatitis/chronic Pelvic Pain Syndrome - Epidemiology
... The annual prevalence in the general population of chronic pelvic pain syndrome is 0.5% ... However, the overall prevalence of symptoms suggestive of CP/CPPS is 6.3% ... The prevalence of symptoms suggestive of CPPS in this selected population was 5.7% in women and 2.7% in men, placing in doubt the role of the prostate gland ...
Chronic Disease In China - Epidemiology
... For example, a clear relation exists between urbanization and the prevalence of diabetes in China (diabetes defined as diabetic symptoms and a random blood glucose concentration of 11.1 ... The rapid environmental changes that follow urbanization are increasing the prevalence of the major risk factors for chronic disease ... The prevalence of current cigarette smoking in men (smoked in the past 30 days) was 57% in 2002, but had fallen from 63% in 1996 less than 3% of women are ...
Misophonia - Prevalence and Comorbidity
... The prevalence of misophonia is currently unknown but groups of people identifying with the condition suggest it is more common than previously recognized ... prevalent in 4-5% of the general population, some surveys report prevalence as high as 60% while prevalence in a 2010 study was measured at 10% ...

More definitions of "prevalence":

  • (noun): A superiority in numbers or amount.
    Synonyms: preponderance
  • (noun): The quality of prevailing generally; being widespread.
    Example: "He was surprised by the prevalence of optimism about the future"

Famous quotes containing the word prevalence:

    The prevalence of suicide, without doubt, is a test of height in civilization; it means that the population is winding up its nervous and intellectual system to the utmost point of tension and that sometimes it snaps.
    Havelock Ellis (1859–1939)

    That the public can grow accustomed to any face is proved by the increasing prevalence of Keith’s ruined physiognomy on TV documentaries and chat shows, as familiar and homely a horror as Grandpa in The Munsters.
    Philip Norman, British author, journalist. The Life and Good Times of the Rolling Stones, introduction (1989)