Preventable fraction for the population

Measure used in epidemiology

In epidemiology, preventable fraction for the population (PFp), is the proportion of incidents in the population that could be prevented by exposing the whole population. It is calculated as $PF_{p}=(I_{p}-I_{e})/I_{p}$ , where $I_{e}$ is the incidence in the exposed group, $I_{p}$ is the incidence in the population.^[1]^[2]

It is used when an exposure reduces the risk, as opposed to increasing it, in which case its symmetrical notion is attributable fraction for the population.^{[citation needed]}

References

^ Porta, Miquel, ed. (2014). "A Dictionary of Epidemiology". Dictionary of Epidemiology - Oxford Reference. Oxford University Press. p. 223. doi:10.1093/acref/9780199976720.001.0001. ISBN 9780199976720. Retrieved 2018-05-09.
^ Rothman, Kenneth J.; Greenland, Sander; Lash, Timothy L. (2012). Modern epidemiology (3rd ed.). Philadelphia: Lippincott Williams & Wilkins. ISBN 9780781755641. OCLC 169455558.

Clinical research and experimental design

Overview

Clinical trial
- Trial protocols
- Adaptive clinical trial
Academic clinical trials
Clinical study design
Evidence-based medicine
Real world evidence
Patient and public involvement

Controlled study
(EBM I to II-1)

Randomized controlled trial
- Scientific experiment
- Blind experiment
- Open-label trial
Adaptive clinical trial
- Platform trial

Observational study
(EBM II-2 to II-3)

Measures

Occurrence	Incidence, Cumulative incidence, Prevalence, Point prevalence, Period prevalence
Association	Risk difference, Number needed to treat, Number needed to harm, Risk ratio, Relative risk reduction, Odds ratio, Hazard ratio
Population impact	Attributable fraction among the exposed, Attributable fraction for the population, Preventable fraction among the unexposed, Preventable fraction for the population
Other	Clinical endpoint, Virulence, Infectivity, Mortality rate, Morbidity, Case fatality rate, Specificity and sensitivity, Likelihood-ratios, Pre- and post-test probability