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Integration Point: Analysis - Dual Endpoints (TTE-TTE or TTE-Binary)

Gabriel Potvin

October 16, 2025

IntegrationPointAnalysisDual.Rmd

to do (now it’s tte copy paste)

←\leftarrow Go back to the Integration Point: Analysis page

Input Variables

When creating a custom R script, you can optionally use specific variables provided by East Horizon’s engine itself. These variables are automatically available and do not need to be set by the user, except for the UserParam variable. Refer to the table below for the variables that are available for this integration point, outcome, and study objective.

Variable Type Description
SimData Data Frame Subject data generated in current simulation, one row per subject. To access these variables in your R code, use the syntax: SimData$NameOfTheVariable, replacing NameOfTheVariable with the appropriate variable name. See below for more information.
DesignParam List Input parameters which may be needed to compute test statistics and perform tests. To access these variables in your R code, use the syntax: DesignParam$NameOfTheVariable, replacing NameOfTheVariable with the appropriate variable name. See below for more information.
LookInfo List Input parameters related to multiple looks. Not applicable when Statistical Design = Fixed Sample.
UserParam List Contains all user-defined parameters specified in the East Horizon interface (refer to the Instructions section). To access these parameters in your R code, use the syntax: UserParam$NameOfTheVariable, replacing NameOfTheVariable with the appropriate parameter name.

Variables of SimData

Click here to explore the variables of SimData.

Variables of DesignParam

Click here to explore the variables of DesignParam.

Variables of LookInfo

Click here to explore the variables of LookInfo.

Expected Output Variable

East Horizon expects an output of a specific type. Refer to the table below for the expected output for this integration point:

Type Description
List A named list containing ErrorCode and one or multiple of the following members: TestStat, HR, Delta, AnalysisTime. See below for more information.

The output list can take different forms.

If LookInfo$FutBdryScale = 2 (Delta scale): Expected Members of the Output List

Members Type Description
TestStat Numeric Value of appropriate test statistic on Wald ﴾Z﴿ scale for the endpoint for which the function is being called.
Delta Numeric Estimate of Delta for the endpoint for which the function is being called. Not applicable if Dual Endpoint = TTE-TTE. Not applicable if function is called for a Time-to-Event endpoint, required if Binary endpoint.
AnalysisTime Numeric Optional. Estimate of analysis time. For interim analyses, equivalent to look time; for final analysis, equivalent to study duration.
ErrorCode Integer Optional. Can be used to handle errors in your script:
– 0: No error.
– Positive Integer: Nonfatal error, the current simulation will be aborted, but the next simulation will proceed.
– Negative Integer: Fatal error, no further simulations will be attempted.

Note: In that case, Delta is used to check for futility and TestStat is used to check for efficacy.

If LookInfo$FutBdryScale = 6 (HR scale): Expected Members of the Output List

Members Type Description
TestStat Numeric Value of appropriate test statistic on Wald ﴾Z﴿ scale for the endpoint for which the function is being called.
HR Numeric Estimate of the hazard ratio for the endpoint for which the function is being called. Not applicable if function is called for a Binary endpoint, required if Time-to-Event endpoint.
AnalysisTime Numeric Optional. Estimate of analysis time. For interim analyses, equivalent to look time; for final analysis, equivalent to study duration.
ErrorCode Integer Optional. Can be used to handle errors in your script:
– 0: No error.
– Positive Integer: Nonfatal error, the current simulation will be aborted, but the next simulation will proceed.
– Negative Integer: Fatal error, no further simulations will be attempted.

Note: In that case, HR is used to check for futility and TestStat is used to check for efficacy.

If LookInfo$FutBdryScale is anything else (or no futility boundary): Expected Members of the Output List

Members Type Description
TestStat Numeric Value of appropriate test statistic on Wald ﴾Z﴿ scale for the endpoint for which the function is being called.
AnalysisTime Numeric Optional. Estimate of analysis time. For interim analyses, equivalent to look time; for final analysis, equivalent to study duration.
ErrorCode Integer Optional. Can be used to handle errors in your script:
– 0: No error.
– Positive Integer: Nonfatal error, the current simulation will be aborted, but the next simulation will proceed.
– Negative Integer: Fatal error, no further simulations will be attempted.

Note: In that case, TestStat is used to check for both efficacy and futility.

Minimal Templates

Your R script could contain a function such as these ones, with a name of your choice. All input variables must be declared, even if they are not used in the script. We recommend always declaring UserParam as a default NULL value in the function arguments, as this will ensure that the same function will work regardless of whether the user has specified any custom parameters in East Horizon.

A detailed template with step-by-step explanations is available here: Analyze.DEP.R.

Minimal Template for LookInfo$FutBdryScale = 2 (Delta scale) 

PerformDecision <- function( SimData, DesignParam, LookInfo = NULL, UserParam = NULL )
{
    nError               <- 0 # Error handling (no error)
    dTestStat            <- 0 # Initialize TestStat
    dDelta               <- 0 # Initialize Delta
    
    # Write the actual code here.
    
    return( list( TestStat = as.double( dTestStat ), Delta = as.double(dDelta), ErrorCode = as.integer( nError ) ) )
}

Minimal Template for LookInfo$FutBdryScale = 6 (HR scale) 

PerformDecision <- function( SimData, DesignParam, LookInfo = NULL, UserParam = NULL )
{
    nError              <- 0 # Error handling (no error)
    dTestStat           <- 0 # Initialize TestStat
    dHR                 <- 0 # Initialize HR
    
    # Write the actual code here.
    
    return( list( TestStat = as.double( dTestStat ), HR = as.double(dHR), ErrorCode = as.integer( nError ) ) )
}

Minimal Template for other LookInfo$FutBdryScale (or no futility boundary) 

PerformDecision <- function( SimData, DesignParam, LookInfo = NULL, UserParam = NULL )
{
    nError              <- 0 # Error handling (no error)
    dTestStat           <- 0 # Initialize TestStat
    
    # Write the actual code here.
    
    return( list( TestStat = as.double( dTestStat ), ErrorCode = as.integer( nError ) ) )
}

Examples

Explore the following examples for more context:

  1. 2-Arm, Dual Endpoints - Analysis