bcmeta function

Bias-Corrected Meta-Analysis for Combining Studies of Different Types and Quality

This function performers a Bayesian meta-analysis to jointly combine different types of studies. The random-effects follows a finite mixture of normal distributions.

bcmeta(
  data,
  mean.mu = 0,
  sd.mu = 10,
  scale.sigma.between = 0.5,
  df.scale.between = 1,
  B.lower = 0,
  B.upper = 10,
  a.0 = 1,
  a.1 = 1,
  nu = 0.5,
  nu.estimate = FALSE,
  b.0 = 1,
  b.1 = 2,
  nr.chains = 2,
  nr.iterations = 10000,
  nr.adapt = 1000,
  nr.burnin = 1000,
  nr.thin = 1
)

Arguments

• data: A data frame with at least two columns with the following names: 1) TE = treatment effect, 2) seTE = the standard error of the treatment effect.
• mean.mu: Prior mean of the overall mean parameter mu, default value is 0.
• sd.mu: Prior standard deviation of mu, the default value is 10.
• scale.sigma.between: Prior scale parameter for scale gamma distribution for the precision between studies. The default value is 0.5.
• df.scale.between: Degrees of freedom of the scale gamma distribution for the precision between studies. The default value is 1, which results in a Half Cauchy distribution for the standard deviation between studies. Larger values e.g. 30 corresponds to a Half Normal distribution.
• B.lower: Lower bound of the bias parameter B, the default value is 0.
• B.upper: Upper bound of the bias parameter B, the default value is 10.
• a.0: Parameter for the prior Beta distribution for the probability of bias. Default value is a0 = 1.
• a.1: Parameter for the prior Beta distribution for the probability of bias. Default value is a1 = 1.
• nu: Parameter for the Beta distribution for the quality weights. The default value is nu = 0.5.
• nu.estimate: If TRUE, then we estimate nu from the data.
• b.0: If nu.estimate = TRUE, this parameter is the shape parameter of the prior Gamma distribution for nu.
• b.1: If nu.estimate = TRUE, this parameter is the rate parameter of the prior Gamma distribution for nu. Note that E(nu) = b.0/b.1 and we need to choose b.0 << b.1.
• nr.chains: Number of chains for the MCMC computations, default 2.
• nr.iterations: Number of iterations after adapting the MCMC, default is 10000. Some models may need more iterations.
• nr.adapt: Number of iterations in the adaptation process, defualt is 1000. Some models may need more iterations during adptation.
• nr.burnin: Number of iteration discared for burnin period, default is 1000. Some models may need a longer burnin period.
• nr.thin: Thinning rate, it must be a positive integer, the default value 1.

Returns

This function returns an object of the class "bcmeta". This object contains the MCMC output of each parameter and hyper-parameter in the model and the data frame used for fitting the model.

Details

The results of the object of the class bcmeta can be extracted with R2jags or with rjags. In addition a summary, a print and a plot functions are implemented for this type of object.

Examples

## Not run:

library(jarbes)

# Example ppvipd data

data(ppvipd)
## End(Not run)

References

Verde, P. E. (2017) Two Examples of Bayesian Evidence Synthesis with the Hierarchical Meta-Regression Approach. Chap.9, pag 189-206. Bayesian Inference, ed. Tejedor, Javier Prieto. InTech.

Verde, P.E. (2021) A Bias-Corrected Meta-Analysis Model for Combining Studies of Different Types and Quality. Biometrical Journal; 1–17.