futilityAnalysis: Futility Analysis Across Interventions for CRT, MST, or SRT Designs

Description

This function performs a Bayesian futility analysis for each intervention group compared to control, across cluster randomized trials (CRT), multisite trials (MST) or simple randomized trials (SRT).

Usage

futilityAnalysis(
  method = c("crt", "mst", "srt"),
  data,
  outcome = "posttest",
  interventions = "interventions",
  Random = "schools",
  Nsim = 10000,
  Threshold = 0.05,
  FutThreshold = 0.8,
  continuous_covariates = NULL,
  categorical_covariates = NULL
)

Value

A data.frame with columns:

Intervention: Intervention group identifier.
Futility: 1 if considered futile (posterior probability < FutThreshold), 0 otherwise.
ProbES: Bayesian posterior probabilities that the observed effect size is greater than or equal to a pre-specified threshold

Arguments

method: The trial design type: "crt", "mst", or "srt".
data: A data frame containing the variables including outcome, predictors, the clustering variable, and the intervention.
outcome: The name of the outcome (post-test) variable.
interventions: A string specifying the intervention variable.
Random: The name of the clustering variable (e.g., schools or sites) for CRT and MST designs.
Nsim: Number of MCMC iterations to be performed. A minimum of 10,000 is recommended to ensure convergence.
Threshold: The effect size threshold for posterior computation (default = 0.05).
FutThreshold: The minimum posterior probability threshold for non-futility (default = 0.8).
continuous_covariates: A character vector specifying the names of continuous covariates.
categorical_covariates: A character vector specifying the names of categorical covariates (converted to factors).

Details

The function loops over each intervention, fits the appropriate Bayesian model (crtBayes, mstBayes, srtBayes), extracts the posterior probability, and determines futility based on the specified probability threshold.

Examples

Run this code

# \donttest{
###Futility analysis of cluster randomized trial###
data(crt4armSimData)
futilityAnalysis(method = "crt", data = crt4armSimData, outcome = "posttest", 
interventions = "interventions", Random = "schools", Nsim = 10000, 
Threshold = 0.05, FutThreshold = 0.8,continuous_covariates = c("pretest"),
categorical_covariates = c("gender", "ethnicity"))

###Futility analysis of multisite trial###
data(mst4armSimData)
futilityAnalysis(method = "mst", data = mst4armSimData, outcome = "posttest",
interventions = "interventions", Random = "schools", Nsim = 10000, 
Threshold = 0.05, FutThreshold = 0.8,continuous_covariates = c("pretest"),
categorical_covariates = c("gender", "ethnicity"))

###Futility analysis of simple randomized trial###
data(srt4armSimData)
futilityAnalysis(method = "srt", data = srt4armSimData, outcome = "posttest",
interventions = "interventions", Nsim = 10000, Threshold = 0.05, FutThreshold = 0.8,
continuous_covariates = c("pretest"), categorical_covariates = c("gender", "ethnicity"))
# }