convertmargin.survival: Function to convert non-inferiority margin for survival...

In Matteo21Q/dani: Design and Analysis of Non-Inferiority Trials

Function to convert non-inferiority margin for survival outcome between summary measures.

Description

Function to convert non-inferiority margin between different summary measures with a survival outcome. Supported summary measures are hazard ratio (HR), difference in restricted mean survival time (DRMST) and difference in surviving proportion (DS).

Usage

  convertmargin.survival(rate.control.expected=NULL, t.expected=NULL,
  p.control.expected=NULL, NI.margin.original, 
  summary.measure.original, summary.measure.target, 
  tau.RMST=NULL, t.DS=NULL, BH.est="exponential", S.control=NULL)

Arguments

rate.control.expected	The expected control event rate. This is the rate parameter of an exponential distribution for event times in the control arm. Note this can be avoided if passing t.expected and p.control.expected.
t.expected	The time at which the control event risk (p.control.expected) is provided. Note this can be avoided if passing rate.control.expected.
p.control.expected	The expected control event risk at t.expected. Note this can be avoided if passing rate.control.expected.
NI.margin.original	The non-inferiority margin on the original scale, i.e. using the original summary measure.
summary.measure.original	The original summary measure on which the non-inferiority margin is specified. One of "HR" (hazard ratio), "DRMST" (difference in restricted mean survival time) or "DS" (difference in surviving proportion).
summary.measure.target	The summary measure in which we want to convert the non-inferiority margin. One of "RD" (risk difference), "RR" (risk ratio), "OR" (odds ratio) or "AS" (arcsine difference).
tau.RMST	The horizon time tau for RMST.
t.DS	The horizon time t for difference in surviving proportion.
BH.est	How should the baseline hazard be estimated in the conversion of the margin? "exponential" assumes the event distribution si exponential, while "surv.func" uses a survival function fitted on some data (e.g. the control arm data from the trial).
S.control	The survival function in the control arm. This is necessary if using BH.est="surv.func".

Value

This function returns the non-inferiority margin in the target summary measure.

Examples

  # Example: HR to DRMST
  p0.expected<-0.1
  t.ex<-3
  NI.margin.HR<-2
  NI.margin.DRMST<-convertmargin.survival(t.expected=t.ex,
     p.control.expected=p0.expected, 
     NI.margin.original=NI.margin.HR, summary.measure.original="HR",
     summary.measure.target="DRMST", tau.RMST=3)
  # Example: DS to HR
  NI.margin.DS<-0.05
  NI.margin.HR<-convertmargin.survival(t.expected=t.ex,
     p.control.expected=p0.expected, 
     NI.margin.original=NI.margin.DS, summary.measure.original="DS",
     summary.measure.target="HR", t.DS=3)
  # Example: DS to DRMST
  NI.margin.DRMST<-convertmargin.survival(t.expected=t.ex,
     p.control.expected=p0.expected, 
     NI.margin.original=NI.margin.DS, summary.measure.original="DS",
     summary.measure.target="DRMST",tau.RMST=3, t.DS=3)
  

Matteo21Q/dani documentation built on Aug. 29, 2024, 12:48 a.m.