sigma_ref: Reference within-study standard deviation

In si4bayesmeta: Sensitivity and Identification for the Bayesian Meta-Analysis

Description

Computes the reference within-study standard deviation through the geometric mean as suggested in equation (7) by Sorbye and Rue (2014).

Usage

sigma_ref(df)

Arguments

df	data frame with one column "sigma" containing the standard deviations sigmai in each study

Value

Refernce standard deviation expressed by the geometric mean as suggested in equation (7) by Sorbye and Rue (2014). Non-negative real number.

References

Sorbye, S., Rue, H. (2014). Scaling intrinsic Gaussian Markov random field priors in spatial modelling. Spatial Statistics 8, 39-51. https://doi.org/10.1016/j.spasta.2013.06.004

Examples

rT<-c(14,4)
nT<-c(61,36)
rC<-c(15,11)
nC<-c(20,36)
  
df = data.frame(y = log((rT*(nC-rC))/(rC*(nT-rT))), # log-odds-ratio
                sigma = sqrt(1/rT+1/(nT-rT)+1/rC+1/(nC-rC)), # SE(log-odds-ratio)
                labels = c(1:2))
  
sigma_ref(df) # 0.620372

si4bayesmeta documentation built on Dec. 16, 2019, 3:39 p.m.