Point prevalence is the proportion of individuals in a population who have a condition of interest at a specific point in time. Period prevalence is the proportion who experience the condition over a specified time-period. This differs from incidence as it includes those who already have the condition at the start if the time period. In the steady state (no epidemics) and when the prevalence in the population is quite low, Prevalence (P) and Incidence (I) are related: P = I x D, where D is the average duration of the disease. Cross-sectional surveys such as population censuses give detailed information on the prevalence of conditions or risk factors, but are less likely to be useful in describing the natural history or progression of a condition. In economic evaluation budget impact analyses tend to rely on prevalence information, whereas cost-effectiveness analyses are generally applicable to incident cohorts (with new developing or progressing disease).

How to cite: Prevalence [online]. (2016). York; York Health Economics Consortium; 2016. https://www.yhec.co.uk/glossary/prevalence/

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