getAccrualTime: Get Accrual Time

Description

Returns a AccrualTime object that contains the accrual time and the accrual intensity.

Usage

getAccrualTime(
  accrualTime = NA_real_,
  ...,
  accrualIntensity = NA_real_,
  maxNumberOfSubjects = NA_real_
)

Arguments

accrualTime

The assumed accrual time for the study, default is c(0,12) (see details).

...

Ensures that all arguments after accrualTime are be named and that a warning will be displayed if unknown arguments are passed.

accrualIntensity

A vector of accrual intensities, default is the relative intensity 0.1 (see details).

maxNumberOfSubjects

The maximum number of subjects.

Value

Returns a AccrualTime object.

Details

accrualTime can also be used to define a non-constant accrual over time. For this, accrualTime needs to be a vector that defines the accrual intervals and accrualIntensity needs to be specified. The first element of accrualTime must be equal to 0. accrualTime can also be a list that combines the definition of the accrual time and accrual intensity accrualIntensity (see below and examples for details). If the length of accrualTime and the length of accrualIntensity are the same (i.e., the end of accrual is undefined), maxNumberOfPatients > 0 needs to be specified and the end of accrual is calculated.

accrualIntensity needs to be defined if a vector of accrualTime is specified. If the length of accrualTime and the length of accrualIntensity are the same (i.e., the end of accrual is undefined), maxNumberOfPatients > 0 needs to be specified and the end of accrual is calculated. In that case, accrualIntensity is given by the number of subjects per time unit. If the length of accrualTime equals the length of accrualIntensity - 1 (i.e., the end of accrual is defined), maxNumberOfPatients is calculated. In that case, accrualIntensity defines the intensity how subjects enter the trial. For example, accrualIntensity = c(1,2) specifies that in the second accrual interval the intensity is doubled as compared to the first accrual interval. The actual accrual intensity is calculated for the calculated maxNumberOfPatients.

Examples

Run this code

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# Case 1

# > End of accrual, absolute accrual intensity and `maxNumberOfSubjects` are given, 
# > `followUpTime`** shall be calculated. 

## Example: vector based definition

accrualTime <- getAccrualTime(accrualTime = c(0, 6, 30), 
    accrualIntensity = c(22, 33), maxNumberOfSubjects = 924) 
accrualTime


## Example: list based definition

accrualTime <- getAccrualTime(list(
    "0 - <6"   = 22,
    "6 - <=30" = 33), 
    maxNumberOfSubjects = 924) 
accrualTime


## Example: how to use accrual time object

getSampleSizeSurvival(accrualTime = accrualTime, pi1 = 0.4, pi2 = 0.2)


# Case 2

# > End of accrual, relative accrual intensity and `maxNumberOfSubjects` are given, 
# > absolute accrual intensity* and `followUpTime`** shall be calculated. 

## Example: vector based definition 

accrualTime <- getAccrualTime(accrualTime = c(0, 6, 30), 
    accrualIntensity = c(0.22, 0.33), maxNumberOfSubjects = 1000) 
accrualTime


## Example: list based definition

accrualTime <- getAccrualTime(list(
    "0 - <6"   = 0.22,
    "6 - <=30" = 0.33), 
    maxNumberOfSubjects = 1000) 
accrualTime


## Example: how to use accrual time object

getSampleSizeSurvival(accrualTime = accrualTime, pi1 = 0.4, pi2 = 0.2)


# Case 3

# > End of accrual and absolute accrual intensity are given, 
# > `maxNumberOfSubjects`* and `followUpTime`** shall be calculated. 

## Example: vector based definition 

accrualTime <- getAccrualTime(accrualTime = c(0, 6, 30), accrualIntensity = c(22, 33)) 


## Example: list based definition

accrualTime <- getAccrualTime(list(
    "0 - <6"   = 22,
    "6 - <=30" = 33)) 
accrualTime


## Example: how to use accrual time object

getSampleSizeSurvival(accrualTime = accrualTime, pi1 = 0.4, pi2 = 0.2)


# Case 4

# > End of accrual, relative accrual intensity and `followUpTime` are given, 
# > absolute accrual intensity** and `maxNumberOfSubjects`** shall be calculated. 

## Example: vector based definition 

accrualTime <- getAccrualTime(accrualTime = c(0, 6, 30), accrualIntensity = c(0.22, 0.33)) 
accrualTime


## Example: list based definition

accrualTime <- getAccrualTime(list(
    "0 - <6"   = 0.22,
    "6 - <=30" = 0.33)) 
accrualTime


## Example: how to use accrual time object

getSampleSizeSurvival(accrualTime = accrualTime, pi1 = 0.4, pi2 = 0.2)


# Case 5

# > `maxNumberOfSubjects` and absolute accrual intensity are given, 
# > absolute accrual intensity*, end of accrual* and `followUpTime`** shall be calculated 

## Example: vector based definition 

accrualTime <- getAccrualTime(accrualTime = c(0, 6), 
    accrualIntensity = c(22, 33), maxNumberOfSubjects = 1000) 
accrualTime


## Example: list based definition

accrualTime <- getAccrualTime(list(
    "0 - <6" = 22,
    "6"      = 33), 
    maxNumberOfSubjects = 1000) 
accrualTime


## Example: how to use accrual time object

getSampleSizeSurvival(accrualTime = accrualTime, pi1 = 0.4, pi2 = 0.2)


# Case 6 (not possible)

# > `maxNumberOfSubjects` and relative accrual intensity are given, 
# > absolute accrual intensity[x], end of accrual* and `followUpTime`** shall be calculated 

## Example: vector based definition 

accrualTime <- getAccrualTime(accrualTime = c(0, 6), 
    accrualIntensity = c(0.22, 0.33), maxNumberOfSubjects = 1000) 
accrualTime


## Example: list based definition

accrualTime <- getAccrualTime(list(
    "0 - <6" = 0.22,
    "6"      = 0.33), 
    maxNumberOfSubjects = 1000) 
accrualTime


## Example: how to use accrual time object

# Case 6 is not allowed and therefore an error will be shown:

tryCatch({	
    getSampleSizeSurvival(accrualTime = accrualTime, pi1 = 0.4, pi2 = 0.2)
}, error = function(e) {
    print(e$message)
})


# Case 7

# > `followUpTime` and absolute accrual intensity are given,  
# > end of accrual** and `maxNumberOfSubjects`** shall be calculated 

## Example: vector based definition 

accrualTime <- getAccrualTime(accrualTime = c(0, 6), accrualIntensity = c(22, 33)) 
accrualTime


## Example: list based definition

accrualTime <- getAccrualTime(list(
    "0 - <6" = 22,
    "6"      = 33)) 
accrualTime


## Example: how to use accrual time object

getSampleSizeSurvival(accrualTime = accrualTime, 
    pi1 = 0.4, pi2 = 0.2, followUpTime = 6)


# Case 8 (not possible)

# > `followUpTime` and relative accrual intensity are given,  
# > absolute accrual intensity[x], end of accrual and `maxNumberOfSubjects` shall be calculated 

## Example: vector based definition 

accrualTime <- getAccrualTime(accrualTime = c(0, 6), accrualIntensity = c(0.22, 0.33)) 
accrualTime


## Example: list based definition

accrualTime <- getAccrualTime(list(
    "0 - <6" = 0.22,
    "6"      = 0.33)) 
accrualTime


## Example: how to use accrual time object

# Case 8 is not allowed and therefore an error will be shown:

tryCatch({	
    getSampleSizeSurvival(accrualTime = accrualTime, pi1 = 0.4, pi2 = 0.2, followUpTime = 6)
}, error = function(e) {
    print(e$message)
})


# How to show accrual time details

# You can use a sample size or power object as argument for function `getAccrualTime`:

sampleSize <- getSampleSizeSurvival(accrualTime = c(0, 6), accrualIntensity = c(22, 53), 
    lambda2 = 0.05, hazardRatio = 0.8, followUpTime = 6)
sampleSize
accrualTime <- getAccrualTime(sampleSize)
accrualTime

# }
# NOT RUN {
# }

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