conduct {DTEBOP2} | R Documentation |
Computes the hazard ratio between post- and pre-separation periods, provides the 95% Bayesian credible interval, and makes a Go/No-Go decision based on the trial data. This function is intended for interim and final analyses in two-arm survival trials with delayed treatment effects.
Description
Computes the hazard ratio between post- and pre-separation hazard rates, along with the 95% Bayesian credible interval. Based on the user-supplied survival data, the function also provides a Go/No-Go decision for interim or final analysis in two-arm survival trials with delayed treatment effects
Usage
conduct(
data_E,
data_C,
median.1,
median.2,
gprior.E_1 = NULL,
gprior.E_2 = NULL,
L,
U,
trunc.para = c(1, 1),
lambda,
gamma,
nmax,
S_likely = (L + U)/2,
value = FALSE
)
Arguments
data_E |
A data frame containing the survival data for the experimental (treatment) arm. The first column should be the observed survival times, and the second column should be the event indicator (1 = event, 0 = censored). |
data_C |
A data frame containing the survival data for the control arm. The format is the same as data_E: first column for observed time, second column for status (1 = event, 0 = censored). |
median.1 |
Numeric. The overall median survival time for the standard-of-care (SOC) arm. |
median.2 |
Numeric. The overall median survival time for the experimental arm. |
gprior.E_1 |
Optional. A numeric vector of length two specifying the shape and scale parameters of the inverse-gamma prior for the pre-separation mean survival time (i.e., 1/hazard rate). If NULL, the default is |
gprior.E_2 |
Optional. A numeric vector of length two specifying the shape and scale parameters of the inverse-gamma prior for the post-separation mean survival time (i.e., 1/hazard rate). If NULL, the default is |
L |
Numeric. The lower bound of the delayed treatment effect (DTE) separation timepoint. |
U |
Numeric. The upper bound of the delayed treatment effect (DTE) separation timepoint. |
trunc.para |
Numeric vector of length two. Specifies the shape and scale parameters of the truncated Gamma prior for the DTE timepoint. |
lambda |
Numeric. Weighting parameter used in the posterior decision function: |
gamma |
Numeric. Exponent parameter used in the posterior decision function: |
nmax |
Integer. Maximum sample size per arm. |
S_likely |
Numeric. The most likely value of the DTE separation timepoint. Defaults to the midpoint of |
value |
If TRUE, returns posterior means, 95% credible intervals, and event rates. Default is FALSE. |
Value
A list with the following components:
posterior_mean |
Posterior mean of the hazard ratio (post- / pre-separation). |
credible_interval |
95% Bayesian credible interval for the hazard ratio. |
event_rates |
Event rates for the experimental arm, control arm, and overall. |
decision |
One of the following trial decisions based on observed data:
|
Examples
conduct(data_E, data_C, median.1 = 2.8, median.2 = 3.5, L = 2, U = 2.5,
trunc.para = c(1, 1), lambda = 0.95, gamma = 1, nmax = 63, S_likely = 2.3)