plotRCDF.pooledArms: Plot Characteristics of the Estimated Distribution of the...

In futility: Interim Analysis of Operational Futility in Randomized Trials with Time-to-Event Endpoints and Fixed Follow-Up

Plot Characteristics of the Estimated Distribution of the Treatment Arm-Pooled Number of Endpoints

Description

Takes the output from the completeTrial.pooledArms function and generates a plot describing characteristics of the estimated distribution of the treatment arm-pooled number of endpoints.

Usage

plotRCDF.pooledArms(
  eventTimeFrame = NULL,
  eventPPcohort = FALSE,
  target,
  plotTarget = TRUE,
  power.axis = TRUE,
  null.TE = 0,
  power.TE = NULL,
  pRandTx = NULL,
  outDate = NULL,
  eventPriorRate,
  eventPriorWeight,
  xlim = NULL,
  xlab = NULL,
  ylab = NULL,
  power.lab = NULL,
  xPosLegend = 0.67,
  fileDir
)

Arguments

eventTimeFrame	a time frame within which endpoints are counted, specified in weeks as c(start, end). If NULL (default), then all endpoints are counted.
eventPPcohort	a logical value. If TRUE, only endpoints in the per-protocol cohort are counted. The default value is FALSE.
target	a vector of target numbers of endpoints for reporting of the estimated probability that the total number of endpoints will be \ge target, with a 95% credible interval
plotTarget	a logical value. If TRUE (default), target lines are added to the plot; if FALSE, they are omitted.
power.axis	a logical value. If TRUE (default), then a top axis is added to the plot, showing power to reject H_0: TE \le null.TE using a 1-sided 0.025-level Wald test if TE = power.TE throughout the trial.
null.TE	a numeric value of treatment efficacy (zero by default) specifying the null hypothesis if power.axis is TRUE
power.TE	a numeric vector of treatment efficacy levels for which power is shown on the top axis. If power.axis is FALSE, then power.TE is ignored.
pRandTx	a numeric value specifying the probability of being randomized into the treatment group. If power.axis is FALSE, then pRandTx is ignored.
outDate	an optional character string used to match legacy output filenames created by older versions of the package (e.g., files starting with censorTrial_). If NULL (default), a default key is used for storing projection summaries.
eventPriorRate	a numeric value of the treatment arm-pooled prior mean incidence rate for the endpoint, expressed as the number of events per person-year at risk
eventPriorWeight	a numeric vector in which each value represents a weight (i.e., a separate scenario) assigned to the prior gamma distribution of the treatment arm-pooled event rate at the time when 50% of the estimated total person-time at risk has been accumulated
xlim	a numeric vector of the form c(xmin, xmax) for the user-specified x-axis limits. If NULL (default), then the computed range of x-axis values will be used.
xlab	a character string for the user-specified x-axis label. If NULL (default), then the label "Total Number of Infections (n)" will be used.
ylab	a character string for the user-specified y-axis label. If NULL (default), then the label "P( Total Number of Infections >= n ) x 100" will be used.
power.lab	a character string for the user-specified power-axis label. If NULL (default), then the label "Power for TE = power.TE (x 100)" will be used.
xPosLegend	a numeric value in [0,1] (0.67 by default) specifying the x-coordinate for the position of the legend
fileDir	a character string specifying a path for the input directory

Value

None. The function is called solely for plot generation.

See Also

completeTrial.pooledArms and plotRCDF.byArm

Examples

arm <- rep(c("C3","T1","T2"), each=250)
schedule <- rbinom(length(arm), 1, 0.01)
entry <- rpois(length(arm), lambda=60)
entry <- entry - min(entry)
last_visit_dt <- entry + runif(length(arm), min=0, max=80)
event <- rbinom(length(arm), 1, 0.01)
dropout <- rbinom(length(arm), 1, 0.02)
dropout[event==1] <- 0
exit <- rep(NA, length(arm))
exit[event==1] <- last_visit_dt[event==1] + 5
exit[dropout==1] <- last_visit_dt[dropout==1] + 5
followup <- ifelse(event==1 | dropout==1, 0, 1)
interimData <- data.frame(arm=arm, schedule2=schedule, entry=entry, exit=exit,
last_visit_dt=last_visit_dt, event=event, dropout=dropout, complete=0,
followup=followup)

weights <- c(0.2, 0.4, 0.6)
tmpdir <- tempfile('futility_example_'); dir.create(tmpdir)
for (j in 1:length(weights)){
  completeTrial.pooledArms(interimData=interimData, nTrials=50, N=1500, enrollRatePeriod=24,
  eventPriorWeight=weights[j], eventPriorRate=0.06, fuTime=80, visitSchedule=seq(0, 80, by=4),
  visitSchedule2=c(0,seq(from=8,to=80,by=12)), saveDir=tmpdir, randomSeed=9)
}

pdf_file <- file.path(tmpdir, paste0('rcdf_pooled_eventPriorRate=', 0.06, '.pdf'))
pdf(file=pdf_file, width=6, height=5)
plotRCDF.pooledArms(target=c(60,30), power.axis=FALSE, eventPriorRate=0.06,
eventPriorWeight=weights, fileDir=tmpdir)
dev.off()

futility documentation built on Feb. 17, 2026, 1:07 a.m.