# Copyright (c) 2022 Merck Sharp & Dohme Corp. a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.
#
# This file is part of the gsDesign2 program.
#
# gsDesign2 is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#' Group sequential design using weighted log-rank test under non-proportional hazards
#'
#' @import tibble tibble
#' @inheritParams gs_design_ahr
#' @inheritParams gs_info_wlr
#' @section Specification:
#' \if{latex}{
#' \itemize{
#' \item Validate if input analysisTimes is a positive number or a positive increasing sequence.
#' \item Validate if input IF is a positive number or positive increasing sequence on (0, 1] with final value of 1.
#' \item Validate if inputs IF and analysisTimes have the same length if both have length > 1.
#' \item Compute information at input analysisTimes using \code{gs_info_wlr()}.
#' \item Compute sample size and bounds using \code{gs_design_npe()}.
#' \item Return a list of design enrollment, failure rates, and bounds.
#' }
#' }
#' \if{html}{The contents of this section are shown in PDF user manual only.}
#'
#' @export
#'
#' @examples
#' library(dplyr)
#' library(mvtnorm)
#' library(gsDesign)
#' library(tibble)
#' library(gsDesign2)
#'
#' # set enrollment rates
#' enrollRates <- tibble(Stratum = "All", duration = 12, rate = 500/12)
#'
#' # set failure rates
#' failRates <- tibble(
#' Stratum = "All",
#' duration = c(4, 100),
#' failRate = log(2) / 15, # median survival 15 month
#' hr = c(1, .6),
#' dropoutRate = 0.001)
#'
#' # -------------------------#
#' # example 1 #
#' # ------------------------ #
#' # Boundary is fixed
#' x <- gsSurv(
#' k = 3,
#' test.type = 4,
#' alpha = 0.025, beta = 0.2,
#' astar = 0, timing = 1,
#' sfu = sfLDOF, sfupar = 0,
#' sfl = sfLDOF, sflpar = 0,
#' lambdaC = 0.1,
#' hr = 0.6, hr0 = 1,
#' eta = 0.01, gamma = 10,
#' R = 12, S = NULL,
#' T = 36, minfup = 24,
#' ratio = 1)
#'
#' gs_design_wlr(
#' enrollRates = enrollRates,
#' failRates = failRates,
#' ratio = 1,
#' alpha = 0.025, beta = 0.2,
#' weight = function(x, arm0, arm1){wlr_weight_fh(x, arm0, arm1, rho = 0, gamma = 0.5)},
#' upper = gs_b,
#' upar = x$upper$bound,
#' lower = gs_b,
#' lpar = x$lower$bound,
#' analysisTimes = c(12, 24, 36))
#'
#' # -------------------------#
#' # example 2 #
#' # ------------------------ #
#' # Boundary derived by spending function
#' gs_design_wlr(
#' enrollRates = enrollRates,
#' failRates = failRates,
#' ratio = 1,
#' alpha = 0.025, beta = 0.2,
#' weight = function(x, arm0, arm1){wlr_weight_fh(x, arm0, arm1, rho = 0, gamma = 0.5)},
#' 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),
#' analysisTimes = c(12, 24, 36))
#'
gs_design_wlr <- function(enrollRates = tibble(Stratum = "All", duration = c(2, 2, 10),
rate = c(3, 6, 9)),
failRates = tibble(Stratum = "All", duration = c(3, 100),
failRate = log(2)/c(9, 18), hr = c(.9, .6),
dropoutRate = rep(.001, 2)),
weight = wlr_weight_fh, approx = "asymptotic",
alpha = 0.025, beta = 0.1, ratio = 1,
IF = NULL, info_scale = c(0, 1, 2),
analysisTimes = 36,
binding = FALSE,
upper = gs_b,
upar = gsDesign(k = 3, test.type = 1, n.I = c(.25, .75, 1), sfu = sfLDOF, sfupar = NULL)$upper$bound,
lower = gs_b,
lpar = c(qnorm(.1), -Inf, -Inf),
test_upper = TRUE,
test_lower = TRUE,
h1_spending = TRUE,
r = 18, tol = 1e-6
){
# --------------------------------------------- #
# check input values #
# --------------------------------------------- #
msg <- "gs_design_wlr(): analysisTimes must be a positive number or positive increasing sequence"
if (!is.vector(analysisTimes,mode = "numeric")) stop(msg)
if (min(analysisTimes - dplyr::lag(analysisTimes, def = 0)) <= 0) stop(msg)
msg <- "gs_design_wlr(): IF must be a positive number or positive increasing sequence on (0, 1] with final value of 1"
if (is.null(IF)){IF <- 1}
if (!is.vector(IF,mode = "numeric")) stop(msg)
if (min(IF - dplyr::lag(IF, def = 0)) <= 0) stop(msg)
if (max(IF) != 1) stop(msg)
msg <- "gs_design_wlr(): IF and analysisTimes must have the same length if both have length > 1"
if ((length(analysisTimes) > 1) & (length(IF) > 1) & (length(IF) != length(analysisTimes))) stop(msg)
# get the info_scale
info_scale <- if(methods::missingArg(info_scale)){2}else{match.arg(as.character(info_scale), choices = 0:2)}
# --------------------------------------------- #
# get information at input analysisTimes #
# --------------------------------------------- #
y <- gs_info_wlr(enrollRates, failRates, ratio = ratio, events = NULL,
analysisTimes = analysisTimes, weight = weight, approx = approx)
finalEvents <- y$Events[nrow(y)]
IFalt <- y$Events / finalEvents
# Check if IF needed for (any) IA timing
K <- max(length(analysisTimes), length(IF))
nextTime <- max(analysisTimes)
if(length(IF) == 1){
IF <- IFalt
}else{
IFindx <- IF[1 : (K-1)]
for(i in seq_along(IFindx)){
if(length(IFalt) == 1){
y <- rbind(tEvents(enrollRates, failRates,
targetEvents = IF[K - i] * finalEvents,
ratio = ratio, interval = c(.01, nextTime)) %>%
mutate(theta = -log(AHR), Analysis = K - i),
y)
}else if(IF[K-i] > IFalt[K-i]){
y[K - i,] <- tEvents(enrollRates, failRates,
targetEvents = IF[K - i] * finalEvents,
ratio = ratio, interval = c(.01, nextTime)) %>%
dplyr::transmute(Analysis = K - i, Time, Events, AHR, theta = -log(AHR), info, info0)
}
nextTime <- y$Time[K - i]
}
}
y$Analysis <- 1:K
y$N <- eAccrual(x = y$Time, enrollRates = enrollRates)
# h1 spending
if(h1_spending){
theta1 <- y$theta
info1 <- y$info
}else{
theta1 <- 0
info1 <- y$info0
}
# --------------------------------------------- #
# combine all the calculations #
# --------------------------------------------- #
suppressMessages(
allout <- gs_design_npe(theta = y$theta, theta1 = theta1,
info = y$info, info0 = y$info0, info1 = info1, info_scale = info_scale,
alpha = alpha, beta = beta, binding = binding,
upper = upper, upar = upar, test_upper = test_upper,
lower = lower, lpar = lpar, test_lower = test_lower,
r = r, tol = tol) %>%
full_join(y %>% select(-c(info, info0, theta)), by = "Analysis") %>%
select(c("Analysis", "Bound", "Time", "N", "Events", "Z",
"Probability", "Probability0", "AHR", "theta", "info", "info0", "IF")) %>%
arrange(Analysis, desc(Bound))
)
# calculate sample size & events
inflac_fct <- (allout %>% filter(Analysis == K, Bound == "Upper"))$info / (y %>% filter(Analysis == K))$info
allout$Events <- allout$Events * inflac_fct
allout$N <- allout$N * inflac_fct
# add `~HR at bound`, `HR generic` and `Nominal p`
allout <- allout %>% mutate(
"~HR at bound" = gsDesign::zn2hr(z = Z, n = Events, ratio = ratio),
"Nominal p" = pnorm(-Z)
)
# --------------------------------------------- #
# return the output #
# --------------------------------------------- #
# bounds table
bounds <- allout %>%
select(all_of(c("Analysis", "Bound", "Probability", "Probability0", "Z", "~HR at bound", "Nominal p" ))) %>%
arrange(Analysis, desc(Bound))
# analysis table
analysis <- allout %>%
select(Analysis, Time, N, Events, AHR, theta, info, info0, IF) %>%
unique() %>%
arrange(Analysis)
# final output
ans <- list(
enrollRates = enrollRates %>% mutate(rate = rate * inflac_fct),
failRates = failRates,
bounds = bounds,
analysis = analysis)
class(ans) <- c("wlr", "gs_design", class(ans))
return(ans)
}
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