oc_stein: Compute operating characteristics using STEIN

In phase12designs: Comprehensive Tools for Running Model-Assisted Phase I/II Trial Simulations

Compute operating characteristics using STEIN

Description

oc_stein() uses the STEIN design to compute operating charateristics of a user-specificed trial scenario. This design uses target toxicity and efficacy rates separately to form the cutoff intervals within a decision map.

Usage

oc_stein(
  ndose,
  target_t,
  lower_e,
  ncohort = 10,
  cohortsize = 3,
  startdose = 1,
  OBD = 0,
  psi1 = 0.2,
  psi2 = 0.6,
  psafe = 0.95,
  pfutility = 0.9,
  ntrial = 10000,
  utilitytype = 1,
  u1,
  u2,
  prob = NULL
)

Arguments

ndose	Integer. Number of dose levels. (Required)
target_t	Numeric. Target toxicity probability. (Required)
lower_e	Numeric. Minimum acceptable efficacy probability. (Required)
ncohort	Integer. Number of cohorts. (Default is 10)
cohortsize	Integer. Size of a cohort. (Default is 3)
startdose	Integer. Starting dose level. (Default is 1)
OBD	Integer. True index of the Optimal Biological Dose (OBD) for the trial scenario. (Default is 0) If set to 0: Random OBD will be selected. Other: Treat this argument as the true OBD.
psi1	Numerical. Highest inefficacious efficacy probability.
psi2	Numerical. Lowest highly-promising efficacy probability.
psafe	Numeric. Early stopping cutoff for toxicity. (Default is 0.95)
pfutility	Numeric. Early stopping cutoff for efficacy. (Default is 0.95)
ntrial	Integer. Number of random trial replications. (Default is 10000)
utilitytype	Integer. Type of utility structure. (Default is 1) If set to 1: Use preset weights (w11 = 0.6, w00 = 0.4) If set to 2: Use (w11 = 1, w00 = 0) Other: Use user-specified values from u1 and u2.
u1	Numeric. Utility parameter w_11. (0-100)
u2	Numeric. Utility parameter w_00. (0-100)
prob	Fixed probability vectors. If not specified, a random scenario is used by default. Use this parameter to provide fixed probability vectors as a list of the following named elements: pE: Numeric vector of efficacy probabilities for each dose level. pT: Numeric vector of toxicity probabilities for each dose level. obd: Integer indicating the index of the true Optimal Biological Dose (OBD). mtd: Integer indicating the index of the true Maximum Tolerated Dose (MTD). For example: prob <- list( pE = c(0.4, 0.5, 0.6, 0.6, 0.6), pT = c(0.1, 0.2, 0.3, 0.4, 0.4), obd = 3, mtd = 2 )

Value

A list containing operating characteristics such as:

bd.sel

OBD selection percentage

od.sel

Favorable dose selection percentage

bd.pts

Average percentage of patients at the OBD

od.pts

Average percentage of patients at the favorable doses

earlystop

Percentage of early stopped trials

overdose

Overdose patients percentage

poorall

Poor allocation percentage

ov.sel

Overdose selection percentage

Examples

oc_stein(
  ndose = 5,
  target_t = 0.3,
  lower_e = 0.4,
  ntrial = 10,
)

phase12designs documentation built on Sept. 2, 2025, 9:09 a.m.