set_clin {psborrow}

Specify parameters for enrollment time, drop-out pattern and analysis start time

Description

This function allows user to specify the enrollment and drop-out rate, and the type of clinical cut-off Date. Both enrollment times and drop-out times follow piece-wise exponential distribution.

Usage

set_clin(gamma, e_itv, CCOD, CCOD_t, etaC, etaE, d_itv)

Arguments

gamma

A vector of rate of enrollment per unit of time

e_itv

A vector of duration of time periods for recruitment with rates specified in gamma. Note that the length of e_itv should be same length as gamma or 1 less.

CCOD

Type of analysis start time. Analysis starts at CCOD_t months after the first or last patient's enrollment if CCOD = "fixed-first" or CCOD = "fixed-last" respectively. Analysis starts when CCOD_t events have been observed if CCOD = "event"

CCOD_t

Time difference between analysis start and first patient's enrollment if CCOD = "fixed-first". Time difference between analysis start and last patient's enrollment if CCOD = "fixed-last". Number of events observed when analysis starts if CCOD = "event". Patients enrolled after the analysis start time are excluded from the analysis

etaC

A vector for dropout rate per unit time for control arm

etaE

A vector for dropout rate per unit time for experimental arm. If left NULL, it uses the same dropout rate as eta.

d_itv

A vector of duration of time periods for dropping out the study with rates specified in etaC and etaE. Note that the length of d_itv should be same length as etaC or 1 less.

Value

A .clinClass class containing information on enrollment time, drop-out pattern and analysis start time

Examples

# set the operational parameter values for the trial
# analysis starts at64 time units after first patient in
set_clin(gamma = 10, e_itv = 4, etaC = 0.003,  CCOD = "fixed-first", CCOD_t = 64)

# analysis starts at 12 time units after last patient in
set_clin(gamma = 2, e_itv = 18, etaC = 0.005,  CCOD = "fixed-last", CCOD_t = 12)