ivsacim {ivsacim}

Fitting a Cumulative Intensity Model for Exposure Effects with Instrumental Variables

Description

ivsacim is used to fit cumulative intensity models for exposure effects with instrumental variables.

Usage

ivsacim(
  time,
  event,
  instrument,
  IV_valid = TRUE,
  treatment_init,
  treatment_shift_time = NULL,
  max_time = NULL,
  max_time_bet = NULL,
  n_sim = 0,
  weights = NULL
)

Arguments

time

the censored event time

event

event indicator

instrument

the instrumental variable

IV_valid

whether assuming IV satisfies the exclusion restriction

treatment_init

the initial treatment assignment

treatment_shift_time

the shift time of each subject, if no shift for a subject, set as 0

max_time

the max time that we threshold for nonconstant effect

max_time_bet

the max time that we threshold for constant effect

n_sim

the number of resampling, set as 0 if no resampling is needed

weights

optional weights used in the estimating equation

Value

ivsacim returns an object of class "ivsacim". An object of class "ivsacim" is a list containing the following components:

stime

an estimate of the baseline hazards function

dB_D

an estimate of the increment of the treatment effect

B_D

an estimate of the treatment effect

beta_D

an estimate of the constant treatment effect

B_D_se

an estimate of the variance covariance matrix of B_D

beta_D_se

an estimate of the constant treatment effect

by_prod

a byproduct, that will used by other functions

Examples

n = 400
event = rbinom(n, 1, 0.8)
IV = rbinom(n, 1, 0.5)
trt_init = IV
trt_shift = rep(0, n)
time = rexp(n)/(0.5 + trt_init * 0.2)
max_t = 3
max_t_bet = 3
n_sim = 0
fit <- ivsacim(time, event, IV, TRUE, trt_init, 
trt_shift, max_t, max_t_bet, n_sim)