rmstat {lrstat} | R Documentation |
Stratified difference in restricted mean survival times
Description
Obtains the stratified restricted mean survival times and difference in restricted mean survival times at given calendar times.
Usage
rmstat(
time = NA_real_,
milestone = NA_real_,
allocationRatioPlanned = 1,
accrualTime = 0L,
accrualIntensity = NA_real_,
piecewiseSurvivalTime = 0L,
stratumFraction = 1L,
lambda1 = NA_real_,
lambda2 = NA_real_,
gamma1 = 0L,
gamma2 = 0L,
accrualDuration = NA_real_,
followupTime = NA_real_,
fixedFollowup = 0L
)
Arguments
time |
A vector of calendar times at which to calculate the restricted mean survival time. |
milestone |
The milestone time at which to calculate the restricted mean survival time. |
allocationRatioPlanned |
Allocation ratio for the active treatment versus control. Defaults to 1 for equal randomization. |
accrualTime |
A vector that specifies the starting time of
piecewise Poisson enrollment time intervals. Must start with 0, e.g.,
|
accrualIntensity |
A vector of accrual intensities. One for each accrual time interval. |
piecewiseSurvivalTime |
A vector that specifies the starting time of
piecewise exponential survival time intervals. Must start with 0, e.g.,
|
stratumFraction |
A vector of stratum fractions that sum to 1. Defaults to 1 for no stratification. |
lambda1 |
A vector of hazard rates for the event in each analysis time interval by stratum for the active treatment group. |
lambda2 |
A vector of hazard rates for the event in each analysis time interval by stratum for the control group. |
gamma1 |
The hazard rate for exponential dropout, a vector of hazard rates for piecewise exponential dropout applicable for all strata, or a vector of hazard rates for dropout in each analysis time interval by stratum for the active treatment group. |
gamma2 |
The hazard rate for exponential dropout, a vector of hazard rates for piecewise exponential dropout applicable for all strata, or a vector of hazard rates for dropout in each analysis time interval by stratum for the control group. |
accrualDuration |
Duration of the enrollment period. |
followupTime |
Follow-up time for the last enrolled subject. |
fixedFollowup |
Whether a fixed follow-up design is used. Defaults to 0 for variable follow-up. |
Value
A data frame containing the following variables:
-
time
: The calendar time at which to calculate the restricted mean survival time. -
subjects
: The number of enrolled subjects. -
milestone
: The milestone time relative to randomization. -
rmst1
: The restricted mean survival time for the treatment group. -
rmst2
: The restricted mean survival time for the control group. -
rmstDiff
: The difference in restricted mean survival times, i.e.,rmst1 - rmst2
. -
vrmst1
: The variance forrmst1
. -
vrmst2
: The variance forrmst2
. -
vrmstDiff
: The variance forrmstDiff
. -
information
: The information forrmstDiff
, equal to1/vrmstDiff
. -
rmstDiffZ
: The Z-statistic value, i.e.,rmstDiff/sqrt(vrmstDiff)
.
Author(s)
Kaifeng Lu, kaifenglu@gmail.com
Examples
# Piecewise accrual, piecewise exponential survivals, and 5% dropout by
# the end of 1 year.
rmstat(time = c(22, 40),
milestone = 18,
allocationRatioPlanned = 1,
accrualTime = seq(0, 8),
accrualIntensity = 26/9*seq(1, 9),
piecewiseSurvivalTime = c(0, 6),
stratumFraction = c(0.2, 0.8),
lambda1 = c(0.0533, 0.0309, 1.5*0.0533, 1.5*0.0309),
lambda2 = c(0.0533, 0.0533, 1.5*0.0533, 1.5*0.0533),
gamma1 = -log(1-0.05)/12,
gamma2 = -log(1-0.05)/12,
accrualDuration = 22,
followupTime = 18, fixedFollowup = FALSE)