gs_power_wlr: Group sequential design power using weighted log rank test...

In gsDesign2: Group Sequential Design with Non-Constant Effect

Group sequential design power using weighted log rank test under non-proportional hazards

Description

Group sequential design power using weighted log rank test under non-proportional hazards

Usage

gs_power_wlr(
  enroll_rate = define_enroll_rate(duration = c(2, 2, 10), rate = c(3, 6, 9)),
  fail_rate = tibble(stratum = "All", duration = c(3, 100), fail_rate = log(2)/c(9, 18),
    hr = c(0.9, 0.6), dropout_rate = rep(0.001, 2)),
  event = c(30, 40, 50),
  analysis_time = NULL,
  binding = FALSE,
  upper = gs_spending_bound,
  lower = gs_spending_bound,
  upar = list(sf = gsDesign::sfLDOF, total_spend = 0.025),
  lpar = list(sf = gsDesign::sfLDOF, total_spend = NULL),
  test_upper = TRUE,
  test_lower = TRUE,
  ratio = 1,
  weight = wlr_weight_fh,
  info_scale = c("h0_h1_info", "h0_info", "h1_info"),
  approx = "asymptotic",
  r = 18,
  tol = 1e-06,
  interval = c(0.01, 1000),
  integer = FALSE
)

Arguments

enroll_rate	Enrollment rates.
fail_rate	Failure and dropout rates.
event	Targeted event at each analysis.
analysis_time	Minimum time of analysis.
binding	Indicator of whether futility bound is binding; default of FALSE is recommended.
upper	Function to compute upper bound.
lower	Function to compute lower bound.
upar	Parameters passed to upper.
lpar	Parameters passed to lower.
test_upper	Indicator of which analyses should include an upper (efficacy) bound; single value of TRUE (default) indicates all analyses; otherwise, a logical vector of the same length as info should indicate which analyses will have an efficacy bound.
test_lower	Indicator of which analyses should include an lower bound; single value of TRUE (default) indicates all analyses; single value FALSE indicated no lower bound; otherwise, a logical vector of the same length as info should indicate which analyses will have a lower bound.
ratio	Experimental:Control randomization ratio (not yet implemented).
weight	Weight of weighted log rank test: "1" = unweighted. "n" = Gehan-Breslow. "sqrtN" = Tarone-Ware. "FH_p[a]_q[b]" = Fleming-Harrington with p=a and q=b.
info_scale	Information scale for calculation. Options are: "h0_h1_info" (default): variance under both null and alternative hypotheses is used. "h0_info": variance under null hypothesis is used. "h1_info": variance under alternative hypothesis is used.
approx	Approximate estimation method for Z statistics. "event_driven" = only work under proportional hazard model with log rank test. "asymptotic".
r	Integer value controlling grid for numerical integration as in Jennison and Turnbull (2000); default is 18, range is 1 to 80. Larger values provide larger number of grid points and greater accuracy. Normally, r will not be changed by the user.
tol	Tolerance parameter for boundary convergence (on Z-scale).
interval	An interval that is presumed to include the time at which expected event count is equal to targeted event.
integer	Logical value integer whether it is an integer design (i.e., integer sample size and events) or not. This argument is commonly used when creating integer design via to_integer().

Value

A list with input parameters, enrollment rate, analysis, and bound.

Specification

The contents of this section are shown in PDF user manual only.

Examples

library(gsDesign)
library(gsDesign2)

# set enrollment rates
enroll_rate <- define_enroll_rate(duration = 12, rate = 500 / 12)

# set failure rates
fail_rate <- define_fail_rate(
  duration = c(4, 100),
  fail_rate = log(2) / 15, # median survival 15 month
  hr = c(1, .6),
  dropout_rate = 0.001
)

# set the targeted number of events and analysis time
target_events <- c(30, 40, 50)
target_analysisTime <- c(10, 24, 30)

# Example 1 ----

# fixed bounds and calculate the power for targeted number of events
gs_power_wlr(
  enroll_rate = enroll_rate,
  fail_rate = fail_rate,
  event = target_events,
  analysis_time = NULL,
  upper = gs_b,
  upar = gsDesign(
    k = length(target_events),
    test.type = 1,
    n.I = target_events,
    maxn.IPlan = max(target_events),
    sfu = sfLDOF,
    sfupar = NULL
  )$upper$bound,
  lower = gs_b,
  lpar = c(qnorm(.1), rep(-Inf, 2))
)

# Example 2 ----
# fixed bounds and calculate the power for targeted analysis time

gs_power_wlr(
  enroll_rate = enroll_rate,
  fail_rate = fail_rate,
  event = NULL,
  analysis_time = target_analysisTime,
  upper = gs_b,
  upar = gsDesign(
    k = length(target_events),
    test.type = 1,
    n.I = target_events,
    maxn.IPlan = max(target_events),
    sfu = sfLDOF,
    sfupar = NULL
  )$upper$bound,
  lower = gs_b,
  lpar = c(qnorm(.1), rep(-Inf, 2))
)

# Example 3 ----
# fixed bounds and calculate the power for targeted analysis time & number of events

gs_power_wlr(
  enroll_rate = enroll_rate,
  fail_rate = fail_rate,
  event = target_events,
  analysis_time = target_analysisTime,
  upper = gs_b,
  upar = gsDesign(
    k = length(target_events),
    test.type = 1,
    n.I = target_events,
    maxn.IPlan = max(target_events),
    sfu = sfLDOF,
    sfupar = NULL
  )$upper$bound,
  lower = gs_b,
  lpar = c(qnorm(.1), rep(-Inf, 2))
)

# Example 4 ----
# spending bounds and calculate the power for targeted number of events

gs_power_wlr(
  enroll_rate = enroll_rate,
  fail_rate = fail_rate,
  event = target_events,
  analysis_time = NULL,
  upper = gs_spending_bound,
  upar = list(sf = gsDesign::sfLDOF, total_spend = 0.025),
  lower = gs_spending_bound,
  lpar = list(sf = gsDesign::sfLDOF, total_spend = 0.2)
)

# Example 5 ----
# spending bounds and calculate the power for targeted analysis time

gs_power_wlr(
  enroll_rate = enroll_rate,
  fail_rate = fail_rate,
  event = NULL,
  analysis_time = target_analysisTime,
  upper = gs_spending_bound,
  upar = list(sf = gsDesign::sfLDOF, total_spend = 0.025),
  lower = gs_spending_bound,
  lpar = list(sf = gsDesign::sfLDOF, total_spend = 0.2)
)

# Example 6 ----
# spending bounds and calculate the power for targeted analysis time & number of events

gs_power_wlr(
  enroll_rate = enroll_rate,
  fail_rate = fail_rate,
  event = target_events,
  analysis_time = target_analysisTime,
  upper = gs_spending_bound,
  upar = list(sf = gsDesign::sfLDOF, total_spend = 0.025),
  lower = gs_spending_bound,
  lpar = list(sf = gsDesign::sfLDOF, total_spend = 0.2)
)

gsDesign2 documentation built on April 3, 2025, 9:39 p.m.