Variables of DesignParam

Gabriel Potvin

October 16, 2025

The variables in DesignParam define the trial design parameters. They can be used in custom scripts for the Analysis Integration Point and the Treatment Selection Integration Point. To access these parameters in your R code, use the syntax: DesignParam$NameOfTheVariable, replacing NameOfTheVariable with the appropriate parameter name.

The tables below describe each variable and notes any conditions under which it can or cannot be used in a project on East Horizon Explore and East Horizon Design. Availability notes are only specified when they differ from the default availability of the integration points (see the pages linked above for details).

For Study Objective = Two Arm Confirmatory

For Endpoint Type = Continuous, Binary, Time-to-Event, Continuous with Repeated Measures

Variable Name	Type	Description	Notes for Explore	Notes for Design
Alpha	Numeric	Type I Error.		Only available if Test Type = One-sided or Two-sided symmetric.
LowerAlpha	Numeric	Lower Type I Error. Same as Alpha if left-tailed one-sided test. Only makes sense to use for two-sided asymmetric tests.	Only available if Tail Type = Left-tailed. Two-sided tests do not exist, so this variable is not useful: use Alpha instead.	Only available if Test Type = One-sided and Tail Type = Left-tailed, or Test Type = Two-sided asymmetric.
UpperAlpha	Numeric	Lower Type I Error. Same as Alpha if right-tailed one-sided test. Only makes sense to use for two-sided asymmetric tests.	Only available if Tail Type = Right-tailed. Two-sided tests do not exist, so this variable is not useful: use Alpha instead.	Only available if Test Type = One-sided and Tail Type = Right-tailed, or Test Type = Two-sided asymmetric.
TrialType	Integer	Trial Type: – 0: Superiority. – 1: Non-inferiority. – 2: Equivalence. – 3: Super-superiority.	Type 2 (equivalence) does not exist.
TestType	Integer	Test Type: – 0: One-sided. – 1: Two-sided symmetric. – 2: Two-sided asymmetric.	Types 1 and 2 (two-sided) do not exist.
TailType	Integer	Nature of critical region: – 0: Left-tailed. – 1: Right-tailed.		Only available if Test Type = One-sided.
AllocInfo	Vector of Numeric	Vector of length equal to the number of treatment arms (number of arms - 1), containing the ratios of the treatment group sample sizes to control group sample size.
CriticalPoint	Numeric	Critical value (for one-sided tests).	Only available if Statistical Design = Fixed Sample.	Only available if Test Type = One-sided and Statistical Design = Fixed Sample.
LowerCriticalPoint	Numeric	Lower critical value. Same as CriticalPoint if left-tailed one-sided test. Only makes sense to use for two-sided asymmetric tests.	Only available if Statistical Design = Fixed Sample and Tail Type = Left-tailed. Two-sided tests do not exist, so this variable is not useful: use CriticalPoint instead.	Only available if Statistical Design = Fixed Sample. Only available if Test Type = One-sided and Tail Type = Left-tailed, or Test Type = Two-sided symmetric/asymmetric.
UpperCriticalPoint	Numeric	Lower critical value. Same as CriticalPoint if right-tailed one-sided test. Only makes sense to use for two-sided asymmetric tests.	Only available if Statistical Design = Fixed Sample and Tail Type = Right-tailed. Two-sided tests do not exist, so this variable is not useful: use CriticalPoint instead.	Only available if Statistical Design = Fixed Sample. Only available if Test Type = One-sided and Tail Type = Right-tailed, or Test Type = Two-sided symmetric/asymmetric.
SampleSize	Integer	Sample size of the trial.
MaxCompleters	Integer	Maximum number of completers.	Not available for Endpoint Type = Time-to-Event and for Vaccine Efficacy (Endpoint Type = Binary with Lower Value and Test = 1 - Ratio of Proportions or 1 - Ratio of Poisson Rates).	Not available for Time-to-Event tests.
RespLag	Numeric	Follow-up duration.	Not available for Endpoint Type = Time-to-Event.	Not available for Time-to-Event tests.
LookFixOption	Integer	Look option: - 0: Event-based. - 1: Time-based.	Not available.	Only available for Time-to-Event tests.
MaxEvents	Integer	Maximum events.	Only available for Endpoint Type = Time-to-Event and for Vaccine Efficacy (Endpoint Type = Binary with Lower Value and Test = 1 - Ratio of Proportions or 1 - Ratio of Poisson Rates).	Only available for Time-to-Event tests.
MaxStudyDur	Integer	Maximum study duration.	Not available.	Only available for Time-to-Event tests with Look Fix Option = 1 (Time-based).
FollowUpType	Integer	Follow-up type: – 0: Until the end of the study. – 1: For a fixed period.	Only available for Endpoint Type = Time-to-Event.	Only available for Time-to-Event tests.
FollowUpDur	Numeric	Follow-up duration.	Only available for Endpoint Type = Time-to-Event.	Only available for Time-to-Event tests.
TestStatType	Integer	Test statistic type. For Time-to-Event tests: - 0: Logrank. - 1: Wilcoxon Gehan. - 2: Harrington Fleming. For Continuous test: - 3: Z-test. - 4: t-test. For Binary test: - 5: Wald. - 6: Score.	Not available.	Not available for Test = Difference of Proportions or Odds Ratio of Proportions (Binary).
HFParam1	Numeric	First parameter of Harrington Fleming.	Not available.	Only available for Time-to-Event tests.
HFParam2	Numeric	Second parameter of Harrington Fleming.	Not available.	Only available for Time-to-Event tests.
VarType	Integer	Variance type. For Continuous test: - 4: Equal - 5: Unequal. For Difference of Proportions (Binary) test: - 0: Pooled. - 1: Unpooled. For Ratio of Proportions (Binary): - 2: Null - 3: Empirical.	Not available.	Not available for Time-to-Event tests or Test = Odds Ratio of Proportions (Binary).
TrtEffNull	Numeric	Treatment effect under null on natural scale.	Not available for Endpoint Type = Continuous with Repeated Measures. Set to 0 for Trial Type = Superiority. Set to $Delta_0 = log(HR_0)$ for Endpoint Type = Time-to-Event. Set to $(1-\rho_0)$ for Vaccine Efficacy (Endpoint Type = Binary with Lower Value and Test = 1 - Ratio of Proportions or 1 - Ratio of Poisson Rates).	Set to 0 for Trial Type = Superiority. Set to $Delta_0 = log(HR_0)$ for Time-to-Event tests.
MuC	Numeric	Design mean for the control arm.	Not available.
Sigma	Numeric	Design standard deviation specified in simulations.	Not available.	Only available for Test = Difference of Means (Continuous) and Test Stat Type = 3 (Z-test).
PiC	Numeric	Design proportion for the control arm.	Not available.	Only available for Binary tests.
NumHzrdPrd	Integer	Number of Hazard pieces.	Not available.	Only available for Time-to-Event tests.
PrdAt	Numeric	Period starting value.	Not available.	Only available for Time-to-Event tests.
LambdaC	Numeric	Control Hazard rate.	Not available.	Only available for Time-to-Event tests.
NumVisit	Integer	Number of visits.	Only available for Endpoint Type = Continuous with Repeated Measures.	Not available.
VisitTime	Vector of Numeric	Vector of length NumVisit, indicating the time for each visit.	Only available for Endpoint Type = Continuous with Repeated Measures.	Not available.
VisitStatus	Vector of Integer	Vector of length NumVisit, indicating the visit selection status for each visit: – 0: Visit has not been selected for analysis. – 1: Visit has been selected for analysis.	Only available for Endpoint Type = Continuous with Repeated Measures.	Not available.
PrimContrastCoeff	Vector of Numeric	Vector of length NumVisit, indicating the primary contrast coefficient for each visit.	Only available for Endpoint Type = Continuous with Repeated Measures.	Not available.
SecContrastCoeff	Vector of Numeric	Vector of length NumVisit, indicating the secondary contrast coefficient for each visit.	Only available for Endpoint Type = Continuous with Repeated Measures. Set to NULL for Statistical Design = Fixed Sample.	Not available.
DropImp	Integer	Dropout imputation method: – 0: None. – 1: Last observation carried forward (LOCF).	Only available for Endpoint Type = Continuous with Repeated Measures.	Not available.
NumStratFactors	Integer	Number of stratification factors.	Only available for Endpoint Type = Time-to-Event with Stratification turned on.	Only available for Time-to-Event tests with Stratification turned on.
StratFactors	Named List	Named list of length NumStratFactors, indicating stratification factors details. For example, StratFactors[“Factor1”] is an array of level names for Factor 1.	Only available for Endpoint Type = Time-to-Event with Stratification turned on.	Only available for Time-to-Event tests with Stratification turned on.
TestStratFactors	Array of Character	Array of factor names included in the analysis. Length is between 1 and NumStratFactors.	Only available for Endpoint Type = Time-to-Event with Stratification turned on.	Not available.
NumSubPops	Integer	Number of subpopulations.	Only available for Endpoint Type = Time-to-Event with Stratification and Subpopulations turned on.	Not available.
SubPops	Array of Character	Array of subpopulation names.	Only available for Endpoint Type = Time-to-Event with Stratification and Subpopulations turned on.	Not available.
WindCond	Integer	Winning condition: - 1: At least subpopulation 1. - 2: At least subpopulation 2. - 3: At least subpopulation 3. - 4: At least subpopulation 4. - 5: At least one subpopulation. - 6: At least two subpopulations. - 7: At least three subpopulations. - 8: At least four subpopulations. - 9: At least full population. - 10: All populations.	Only available for Endpoint Type = Time-to-Event with Stratification and Subpopulations turned on.	Not available.
PlanEndTrial	Integer	Planned end of trial: - 1: Subpopulation 1. - 2: Subpopulation 2. - 3: Subpopulation 3. - 4: Subpopulation 4. - 5: Full population.	Only available for Endpoint Type = Time-to-Event with Stratification and Subpopulations turned on.	Not available.
TransitionMatrix	Matrix of Numeric	Transition matrix between all populations, including full population and subpopulations. Dimension of (NumSubPops + 1) x (NumSubPops + 1).	Only available for Endpoint Type = Time-to-Event with Stratification and Subpopulations turned on.	Not available.
PropAlpha	Vector of Numeric	Vector of length (NumSubPops + 1), indicating the proportion of alpha for all populations, including full population and subpopulations.	Only available for Endpoint Type = Time-to-Event with Stratification and Subpopulations turned on.	Not available.

For Endpoint Type = Dual (TTE-TTE or TTE-Binary)

Variable Name	Type	Description	Notes for Explore
EndpointType	Vector of Integer	Vector of length equal to the number of endpoints, indicating the endpoint types: – 0: Continuous. – 1: Binary. – 2: Time-to-Event.
EndpointName	Vector of Character	Vector of length equal to the number of endpoints, indicating the endpoint names.
WinCond	Integer	Winning condition: - 1: At least endpoint 1. - 2: At least endpoint 2. - 3: At least one endpoint. - 4: Both endpoints.
TailType	Named List of Integer	Named List of length equal to the number of endpoints, indicating the nature of critical region for each endpoint. For example, TailType[“Endpoint 1”] is the nature for Endpoint 1. Possible values: – 0: Left-tailed. – 1: Right-tailed.
FollowUpType	Named List of Integer	Named List of length equal to the number of endpoints, indicating the follow-up type for each endpoint. For example, FollowUpType[“Endpoint 1”] is the type for Endpoint 1. Possible values: – 0: Until the end of the study. – 1: For a fixed period.
FollowUpDur	Named List of Numeric	Named List of length equal to the number of endpoints, indicating the follow-up duration for each endpoint. For example, FollowUpDur[“Endpoint 1”] is the duration for Endpoint 1.
TrialType	Named List of Integer	Named List of length equal to the number of endpoints, indicating the trial type for each endpoint. For example, TrialType[“Endpoint 1”] is the type for Endpoint 1. Possible values: – 0: Superiority. – 1: Non-inferiority.
VarType	Integer	Variance type: - 0: Pooled. - 1: Unpooled.	Only available for Dual Endpoint = TTE-Binary.
PlanEndTrial	Integer	Planned end of trial: - 1: Full information for both endpoints. - 2: Full information for endpoint 1. - 3: Full information for endpoint 2.
AllocInfo	Vector of Numeric	Vector of length equal to the number of treatment arms (number of arms - 1), containing the ratios of the treatment group sample sizes to control group sample size.
Alpha	Numeric	Type I Error.
CriticalPoint	Named List of Numeric	Named List of length equal to the number of endpoints, indicating the critical value for each endpoint. For example, CriticalPoint[“Endpoint 1”] is the value for Endpoint 1.	Only available if Statistical Design = Fixed Sample.
LowerCriticalPoint	Named List of Numeric	Named List of length equal to the number of endpoints, indicating the lower critical value for each endpoint. For example, LowerCriticalPoint[“Endpoint 1”] is the value for Endpoint 1.	Only available if Statistical Design = Fixed Sample and Tail Type = Left Tailed.
UpperCriticalPoint	Named List of Numeric	Named List of length equal to the number of endpoints, indicating the upper critical value for each endpoint. For example, LowerCriticalPoint[“Endpoint 1”] is the value for Endpoint 1.	Only available if Statistical Design = Fixed Sample and Tail Type = Right Tailed.
SampleSize	Integer	Sample size of the trial.
MultAdj	Integer	Multiplicity adjustment method: - 0: None. - 1: Fallback. - 2: Fixed sequence. - 3: Weighted Bonferroni. - 4: Weighted Bonferroni-Holms. - 5: Weighted Hochberg.	Only available if the multiplicity adjustment method is not custom.
TestOrder	Integer	Testing order: - 1: Start with endpoint 1. - 2: Start with endpoint 2.	Only available if Multiplicity Adjustment = 1 (Fallback) or 2 (Fixed Sequence).
MaxEvents	Named List of Integer	Named List of length equal to the number of endpoints, indicating the maximum events for each endpoint. For example, MaxEvents[“Endpoint 1”] is the maximum events for Endpoint 1.	Set to NA for endpoints with Endpoint Type = Binary.
MaxCompleters	Named List of Integer	Named List of length equal to the number of endpoints, indicating the maximum number of completers for each endpoint. For example, MaxCompleters[“Endpoint 1”] is the maximum number of completers for Endpoint 1.	Not available for Dual Endpoint = TTE-TTE. Set to NA for endpoints with Endpoint Type = Time-to-Event.
TrtEffNull	Named List of Numeric	Named List of length equal to the number of endpoints, indicating the treatment effect under the null hypothesis for each endpoint. For example, TrtEffNull[“Endpoint 1”] is the treatment effect for Endpoint 1.	Specified in natural log scale for endpoints with Endpoint Type = Time-to-Event.
AlphaAlloc	Named List of Numeric	Named List of length equal to the number of endpoints, indicating the type I error allocation (%) for each endpoint. For example, AlphaAlloc[“Endpoint 1”] is the error allocation for Endpoint 1.	Not available for Multiplicity Adjustment = 0 (None) or 2 (Fixed Sequence).
TargetSSFA	Named List of Numeric	Named List of length equal to the number of endpoints, indicating the target sample size (final analysis) for each endpoint. For example, TargetSSFA[“Endpoint 1”] is the target sample size for Endpoint 1.	Not available for Dual Endpoint = TTE-TTE. Set to NA for endpoints with Endpoint Type = Time-to-Event.
TestStat	Named List of Numeric	Named List of length equal to the number of endpoints, indicating the test statistic output for each endpoint. For example, TestStat[“Endpoint 1”] is the test statistic output for Endpoint 1.	Set to NA for endpoints with a pending analysis. For example, if “Endpoint 1” is tested first, then for the analysis of “Endpoint 1” we will have TestStat[“Endpoint 2”] = NA.

Notes:

• Dual endpoints are not available for East Horizon: Design.
• “Endpoint 1” is used as a sample endpoint name. It will be the actual endpoint name as specified by the user.

For Study Objective = Multiple Arm Confirmatory or Dose Finding

Variable Name	Type	Description	Notes for Explore	Notes for Design
Alpha	Numeric	Type I Error.
TrialType	Integer	Trial Type: – 0: Superiority.
TestType	Integer	Test Type: – 0: One-sided.
TailType	Integer	Nature of critical region: – 0: Left-tailed. – 1: Right-tailed.
InitialAllocInfo	Vector of Numeric	Vector of length equal to the number of treatment arms (number of arms - 1), containing the ratios of the treatment group sample sizes to control group sample size.
CriticalPoint	Numeric	Critical value.	Only available if Statistical Design = Fixed Sample. Not available for Study Objective = Dose Finding.	Not available for Combining P-Values (MAMS) tests.
SampleSize	Integer	Sample size of the trial.
MaxCompleters	Integer	Maximum number of completers.	Not available for Endpoint Type = Time-to-Event.	Not available for Time-to-Event tests.
RespLag	Numeric	Follow-up duration.	Not available for Endpoint Type = Time-to-Event.	Not available for Time-to-Event tests and for for Combining P-Values (MAMS) tests .
MaxEvents	Integer	Maximum events.	Only available for Endpoint Type = Time-to-Event. Not available for Study Objective = Dose Finding.	Only available for Time-to-Event tests.
FollowUpType	Integer	Follow-up type: – 0: Until the end of the study. – 1: For a fixed period.	Only available for Endpoint Type = Time-to-Event. Not available for Study Objective = Dose Finding.	Only available for Time-to-Event tests.
FollowUpDur	Numeric	Follow-up duration.	Only available for Endpoint Type = Time-to-Event. Not available for Study Objective = Dose Finding.	Only available for Time-to-Event tests.
TestStatType	Integer	Test statistic type: - 3: Z-test. - 4: t-test.	Only available for Endpoint Type = Continuous.	Only available for Continuous tests.
VarType	Integer	Variance type. For Continuous test: - 4: Equal - 5: Unequal. For Difference of Proportions (Binary) test: - 0: Pooled. 1: Unpooled.	Not available for Endpoint Type = Timne-to-Event.	Not available for Time-to-Event tests.
Sigma	Numeric	Design standard deviation specified in simulations.	Not available.	Only available for Test = MAMS Difference of Means: Combining P-Values (Continuous) and Test Stat Type = 3 (Z-test).
PValCombMethod	Integer	P-value combination method: - 0: Inverse normal.	Not available.	Only available for Combining P-Values (MAMS) tests.
w1	Numeric	Inverse normal weights for stage 1.	Not available.	Only available for Combining P-Values (MAMS) tests.
w2	Numeric	Inverse normal weights for stage 2.	Not available.	Only available for Combining P-Values (MAMS) tests.
MultAdjMethod	Integer	Multiple comparison procedure.	Possible values:- – 0: Bonferroni. – 3: Dunnett’s Single Step. – 4: Weighted Bonferroni. – 5: Fixed Sequence. – 6: Fallback. – 7: Hochberg’s Step Up.	Possible values:- – 0: Bonferroni. – 1: Sidak. – 2: Simes. – 3: Dunnett’s Single Step. – 4: Weighted Bonferroni. – 5: Fixed Sequence. – 6: Fallback. – 7: Hochberg’s Step Up. – 10: Holm’s Step Down. – 11: Hommel’s Step Up. – 12: Dunnett’s Step Down. – 13: Dunnett’s Step Up.
NumTreatments	Integer	Number of treatment arms (number of arms - 1).
AlphaProp	Vector of Numeric	Vector of length DesignParam$NumTreatments (number of arms - 1), containing the proportion of Alpha for each treatment arm.	Only available for Multiple Comparison Procedure = 4 (Weighted Bonferroni) or 6 (Fallback). Not available for Study Objective = Dose Finding.	Only available for Multiple Comparison Procedure = 4 (Weighted Bonferroni) or 6 (Fallback). Not available for Test = MAMS Difference of Means: Combining P-Values (Continuous) or MAMS Difference of Proportions: Combining P-Values (Binary) or MAMS Logrank (Time-to-Event).
TestSeq	Vector of Integer	Vector of length DesignParam$NumTreatments (number of arms - 1), containing the test sequence for each comparison (each treatment arm).	Only available for Multiple Comparison Procedure = 5 (Fixed Sequence) or 6 (Fallback). Not available for Study Objective = Dose Finding.	Only available for Multiple Comparison Procedure = 5 (Fixed Sequence) or 6 (Fallback). Not available for Test = MAMS Difference of Means: Combining P-Values (Continuous) or MAMS Difference of Proportions: Combining P-Values (Binary) or MAMS Logrank (Time-to-Event).
IsArmPresent	Vector or Integer.	Vector of length DesignParam$NumTreatments (number of arms - 1), indicating whether each arm is still in the trial or was dropped in the interim: - 0: Dropped in the interim. - 1: Still present.	Fixed to 1 for the first look and for Statistical Design = Fixed Sample.	Fixed to 1 for the first look and for Statistical Design = Fixed Sample.
UpdatedAllocInfo	Vector of Numeric	Vector of length DesignParam$NumTreatments (number of arms - 1), containing the updated ratios of the treatment group sample sizes to control group sample size, which may have been updated during treatment selection.