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The Population Attributable Risk (PAR) Percent

Purpose: To use the Population Attributable Risk (PAR) Percent to estimate the impact of a given exposure or risk factor in a population.

Description

The Population Attributable Risk (PAR) Percent is an epidemiologist tool for estimating the amount of disease or condition in a population that can be attributable to an exposure or risk factor. The equation used is also referred to as the Levin formula.


 

population attributable risk (PAR) percent =

= 100 * ((proportion of total population exposed) * ((relative risk for exposed vs nonexposed) - 1)) / (((proportion of total population exposed) * ((relative risk for exposed vs nonexposed) - 1)) + 1)

 

where:

• The proportion is the decimal fraction from 0 to 1.00.

• As indicated in the previous section, the odds ratio can be used for the risk ratio, if the incidence of the condition is < 10%. (See also page 146 of Fitzgerald, 1996).

 

Interpretation:

• This gives a rough estimate of the amount of disease or condition which could be removed by eliminating the exposure or risk factor.


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Objective

ICD-10