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Egger's Regression Test for Small-Study Effects (Bayesian)

Usage

egger(
  data,
  studyvar,
  n_ctrl,
  n_int,
  event_ctrl = NULL,
  event_int = NULL,
  mean_ctrl = NULL,
  mean_int = NULL,
  sd_ctrl = NULL,
  sd_int = NULL,
  likelihood = c("binomial", "gaussian", "poisson"),
  heterogeneity = c("multiplicative", "additive"),
  alpha_prior = NULL,
  beta_prior = NULL,
  kappa_prior = NULL,
  gamma_prior = NULL,
  d_prior = NULL,
  tau_prior = NULL,
  credible_level = 0.9,
  chains = 4,
  iter_warmup = 2000,
  iter_sampling = 4000,
  adapt_delta = 0.95,
  seed = 1234,
  custom_model = NULL,
  custom_data = NULL,
  ...
)

Arguments

data

A data frame with one row per study.

studyvar

Character. Column name of the study identifier.

n_ctrl, n_int

Character. Column names of control and intervention sample sizes.

event_ctrl, event_int

Character. Column names of event counts (binomial / Poisson likelihoods).

mean_ctrl, mean_int, sd_ctrl, sd_int

Character. Column names of arm means and SDs (Gaussian likelihood).

likelihood

Character. One of "binomial", "gaussian", "poisson".

heterogeneity

Character. "multiplicative" (default) or "additive".

alpha_prior

Prior on the intercept.

beta_prior

Prior on the slope (the Egger coefficient).

kappa_prior

Prior on the multiplicative heterogeneity coefficient.

gamma_prior

Prior on the dispersion parameter.

d_prior

Prior on the overdispersion parameter.

tau_prior

Prior on the between-study SD for additive heterogeneity.

credible_level

Numeric in (0, 1). Credible-interval level. Default 0.90.

chains, iter_warmup, iter_sampling, adapt_delta, seed

MCMC settings.

custom_model

Optional character scalar of Stan code overriding the generated program.

custom_data

Optional named list merged into the Stan data list.

...

Passed to cmdstanr::sample().

Value

An object of class c("bayesma_egger", "bayesma").