Comparing SMDs between ndependent studies with bootstrapping

[Stable]

A function to compare standardized mean differences (SMDs) between studies. This function is intended to be used to compare the compatibility of original studies with replication studies (lower p-values indicating lower compatibility).

boot_compare_smd(
  x1,
  y1 = NULL,
  x2,
  y2 = NULL,
  null = 0,
  paired = FALSE,
  alternative = c("two.sided", "less", "greater"),
  R = 1999,
  alpha = 0.05
)

Arguments

x1

a (non-empty) numeric vector of data values from study 1.

y1

an optional (non-empty) numeric vector of data values from study 1.

x2

a (non-empty) numeric vector of data values from study 2.

y2

an optional (non-empty) numeric vector of data values from study 2.

null

a number indicating the null hypothesis. For TOST, this would be equivalence bound.

paired

a logical indicating whether the SMD is from a paired or independent samples design.

alternative

a character string specifying the alternative hypothesis, must be one of "two.sided" (default), "greater" or "less". You can specify just the initial letter.

R

number of bootstrap replicates

alpha

alpha level (default = 0.05)

Value

A list with class "htest" containing the following components:

  • "statistic": z-score.

  • "p.value": numeric scalar containing the p-value for the test under the null hypothesis.

  • "estimate": difference in SMD between studies

  • "conf.int": percentile (bootstrap) confidence interval for difference in SMDs

  • "null.value": the specified hypothesized value for the null hypothesis.

  • "alternative": character string indicating the alternative hypothesis (the value of the input argument alternative). Possible values are "greater", "less", or "two-sided".

  • "method": Type of SMD.

  • "data.name": "Boostrapped" to denote summary statistics were utilized to obtain results.

  • "smd": SMDs input for the function.

  • "df_ci": Data frame of confidence intervals.

  • "boot_res": List of bootstrapped results.

  • "call": the matched call.

See also

Other compare studies: boot_compare_cor(), compare_cor(), compare_smd()