rmdiff: Estimate of Restricted Mean Survival Time Difference

In trtswitch: Treatment Switching

Estimate of Restricted Mean Survival Time Difference

Description

Obtains the estimate of restricted mean survival time difference between two treatment groups.

Usage

rmdiff(
  data,
  stratum = "",
  treat = "treat",
  time = "time",
  event = "event",
  milestone = 0,
  rmstDiffH0 = 0,
  conflev = 0.95,
  biascorrection = FALSE
)

Arguments

data	The input data frame that contains the following variables: stratum: The stratum. treat: The treatment. time: The possibly right-censored survival time. event: The event indicator.
stratum	The name of the stratum variable in the input data.
treat	The name of the treatment variable in the input data.
time	The name of the time variable in the input data.
event	The name of the event variable in the input data.
milestone	The milestone time at which to calculate the restricted mean survival time.
rmstDiffH0	The difference in restricted mean survival times under the null hypothesis. Defaults to 0 for superiority test.
conflev	The level of the two-sided confidence interval for the difference in restricted mean survival times. Defaults to 0.95.
biascorrection	Whether to apply bias correction for the variance estimate of individual restricted mean survival times. Defaults to no bias correction.

Value

A data frame with the following variables:

• milestone: The milestone time relative to randomization.

• rmstDiffH0: The difference in restricted mean survival times under the null hypothesis.

• rmst1: The estimated restricted mean survival time for the treatment group.

• rmst2: The estimated restricted mean survival time for the control group.

• rmstDiff: The estimated difference in restricted mean survival times.

• vrmst1: The variance for rmst1.

• vrmst2: The variance for rmst2.

• sermstDiff: The standard error for rmstDiff.

• rmstDiffZ: The Z-statistic value.

• rmstDiffPValue: The two-sided p-value.

• lower: The lower bound of confidence interval.

• upper: The upper bound of confidence interval.

• conflev: The level of confidence interval.

• biascorrection: Whether to apply bias correction for the variance estimate of individual restricted mean survival times.

Author(s)

Kaifeng Lu, [e-mail]

Examples

rmdiff(data = rawdata[rawdata$iterationNumber == 1, ], 
       stratum = "stratum", treat = "treatmentGroup",
       time = "timeUnderObservation", event = "event",
       milestone = 12)

trtswitch documentation built on Jan. 10, 2026, 5:08 p.m.