ARD_from_RR {metaHelper}

Absolute Risk Difference

Description

Calculates the Absolute Risk Difference (ARD) from a Risk Ratio and baseline risk using simulations. The result is ARD as a decimal. The number of replications is fixed at 100,000.

Usage

ARD_from_RR(BR, BRLL, BRUL, RR, RRLL, RRUL, seed = 1)

Arguments

BR

baseline risk

BRLL

baseline risk lower limit confidence interval

BRUL

baseline risk upper limit confidence interval

RR

risk ratio

RRLL

risk ratio lower limit confidence interval

RRUL

risk ratio upper limit confidence interval

seed

seed that is used for the simulation to ensure reproducibility

Value

Named numeric vector containing median ARD, the lower and upper CI of the ARD.

References

Murad M H, Wang Z, Zhu Y, Saadi S, Chu H, Lin L et al. Methods for deriving risk difference (absolute risk reduction) from a meta-analysis BMJ 2023; 381 :e073141 doi:10.1136/bmj-2022-073141

Examples

# Input : Baseline risk and 95% CI (BR BRLL and BRUL), risk ratio and 95% CI (RR, RRLL, RRUL)
BR <- 0.053; BRLL <- 0.039; BRUL <- 0.072
RR <- 0.77; RRLL <- 0.63; RRUL <- 0.94
ARD_from_RR(BR, BRLL, BRUL, RR, RRLL, RRUL)