Preventive fraction
Encyclopedia
Preventive fraction also called preventable fraction, is a calculation that can be derived from relative risk
or odds ratio
.
It may be used when an exposure seems to reduce the risk (in opposition to attributable risk percent
), and gives the percentage of cases that can be prevented if a population is exposed to an intervention, compared to an unexposed population.
It can be calculated as ( 1 − relative risk
) or as ( 1 − odds ratio
).
Relative risk
In statistics and mathematical epidemiology, relative risk is the risk of an event relative to exposure. Relative risk is a ratio of the probability of the event occurring in the exposed group versus a non-exposed group....
or odds ratio
Odds ratio
The odds ratio is a measure of effect size, describing the strength of association or non-independence between two binary data values. It is used as a descriptive statistic, and plays an important role in logistic regression...
.
It may be used when an exposure seems to reduce the risk (in opposition to attributable risk percent
Attributable risk percent
Attributable risk percent is a calculation that can be derived from attributable risk.It gives the portion of cases attributable to this exposure in relation to all cases.It can be calculated as / relative risk....
), and gives the percentage of cases that can be prevented if a population is exposed to an intervention, compared to an unexposed population.
It can be calculated as ( 1 − relative risk
Relative risk
In statistics and mathematical epidemiology, relative risk is the risk of an event relative to exposure. Relative risk is a ratio of the probability of the event occurring in the exposed group versus a non-exposed group....
) or as ( 1 − odds ratio
Odds ratio
The odds ratio is a measure of effect size, describing the strength of association or non-independence between two binary data values. It is used as a descriptive statistic, and plays an important role in logistic regression...
).