# relative.risk: Relative risk calculation In BioProbability: Probability in Biostatistics

## Description

This function calculates the relative risk from a contingency table. Furthermore, a confidence interval for the relative risk is provided. Details on the confidence interval can be found in Agresti (2018, ISBN: 978-1-119-40528-3).

## Usage

 `1` ```relative.risk(A, show.matrix = FALSE, conf.int = FALSE, level = 0.05) ```

## Arguments

 `A` a 2x2 matrix object where A[1,1] contains the number of people with the disease who have been exposed to some condition; A[1,2], the number of people without the disease who have not been exposed this condition; A[2,1], the number of people with the disease who have been exposed to the condition; A[2,2], the number of people without the disease who have not been exposed to some condition. `show.matrix` a logical value indicating whether the matrix A must be shown. `conf.int` a logical value indicating whether a confidence interval for the relative risk must be calculated. `level` level of significance for the confidence interval.

## Value

If `conf.int=TRUE`, a list of length equal to two. The first element of the list `Relative Risk` corresponds to the estimation of the relative risk; the second one `Confidence Interval of level` contains the corresponding confidence interval.

If `conf.int=FALSE`, a numeric value corresponding to the estimation of the relative risk.

## References

Agresti, A. (2018). An introduction to categorical data analysis. John Wiley & Sons. ISBN: 978-1-119-40528-3.

## Examples

 ```1 2 3``` ```A<-matrix(c(744,231,421,659),nrow=2) relative.risk(A,show.matrix=TRUE,conf.int=TRUE) relative.risk(A,show.matrix=TRUE,conf.int=TRUE,level=0.1) ```

BioProbability documentation built on Jan. 25, 2020, 1:06 a.m.