REmrt: Random effects meta-tree

In XinruLI/metacartv0.1.0: Meta-CART: A Flexible Approach to Identify Moderators in Meta-Analysis

Description

A function to fit a random effects meta-tree

Usage

REmrt(formula, data, vi, c = 1, maxL = 5L, minsplit = 2L, delQ = 0.001,
  minbucket = 3, n.fold = 10, lookahead = FALSE, ...)

Arguments

formula	A formula, with a response variable (usually the effect size) and the potential moderator variables but no interaction terms.
data	A data frame of a meta-analytic data set, including the study effect sizes, sampling variance, and the potential moderators.
vi	sampling variance of the effect size.
c	A non-negative scalar.The pruning parameter to prune the initial tree by the "c*standard-error" rule.
maxL	the maximum number of splits
minsplit	the minimum number of studies in a parent node before splitting
delQ	the stopping rule for the decrease of between-subgroups Q. Any split that does not decrease the between-subgroups Q is not attempted.
minbucket	the minimum number of the studies in a terminal node
n.fold	the number of folds to perform the cross-validation
lookahead	an argument indicating whether to apply the "look-ahead" strategy when fitting the tree
...	Additional arguments to be passed.

Value

If no moderator effect is detected, the function will return a list including the following objects:

n: The total number of the studies

Q: The Q-statistics for the heterogeneity test

df: The degree of freedoms of the heterogeneity test

pval.Q: The p-value for the heterogeneity test

g: The summary effect size for all studies (i.e., the overall effect size)

se: The standard error of the summary effect size

zval: The test statistic of the summary effect size

pval: The p-value for the test statistic of the summary effect size

ci.lb: The lower bound of the confidence interval for the summary effect size

ci.ub: The upper bound of the confidence interval for the summary effect size

call: The matched call

If (a) moderator effect(s) is(are) detected, the function will return a list including the following objects:

tree: A data frame that represents the tree, with the Q-between and the residual heterogeneity (tau^2) after each split.

n: The number of the studies in each subgroup

moderators: the names of identified moderators

Qb: The between-subgroups Q-statistic

tau2: The estimate of the residual heterogeneity

df: The degrees of freedom of the between-subgroups Q test

pval.Qb: The p-value of the between-subgroups Q test

g: The subgroup summary effect size, based on Hedges'g

se: The standard error of subgroup summary effect size

zval: The test statistic of the subgroup summary effect size

pval: The p-value of the test statistic of the subgroup summary effect size

ci.lb: The lower bound of the confidence interval

ci.ub: The upper bound of the confidence interval

call: The matched call

cv.res: The cross-validation table

data: the data set subgrouped by the fitted tree

See Also

summary.REmrt, plot.REmrt

Examples

data(dat.BCT2009)
REtree <- REmrt(g ~ T1 + T2+ T4 +T25, vi = vi, data = dat.BCT2009, c = 0)
summary(REtree)

XinruLI/metacartv0.1.0 documentation built on May 14, 2019, 10:32 a.m.