Preventable fraction among the unexposed explained

In epidemiology, preventable fraction among the unexposed (PFu), is the proportion of incidents in the unexposed group that could be prevented by exposure. It is calculated as

PF _{u} = (I _{u} - I _{e)/I} _{u} = 1 - RR , where I _{e} is the incidence in the exposed group, I _{u} is the incidence in the unexposed group, and RR is the relative risk.^{[1] [2]} It is a synonym of the relative risk reduction.

It is used when an exposure reduces the risk, as opposed to increasing it, in which case its symmetrical notion is attributable fraction among the exposed.__TOC__

See also

• Population Impact Measures
• Preventable fraction for the population

Notes and References

1. Book: Aschengrau, Ann. Essentials of epidemiology in public health. Seage. George R.. 2014. Jones & Bartlett Learning. 9781449657338. 3rd. Burlington, MA. 67. 826123155.
2. Book: Rothman, Kenneth J.. Modern epidemiology. Greenland. Sander. Lash. Timothy L.. Lippincott Williams & Wilkins. 2012. 9780781755641. 3rd. Philadelphia. 169455558.