SafetyWindowSize

SafetyWindowSize is the class for safety window length based on cohort size. This class is used to decide the rolling rule from the clinical perspective.

Usage

SafetyWindowSize(gap, size, follow, follow_min)

.DefaultSafetyWindowSize()

Arguments

gap

see slot definition.

size

see slot definition.

follow

see slot definition.

follow_min

see slot definition.

Slots

gap

(list)
observed period of the previous patient before the next patient can be dosed. This is used as follows. If for instance, the cohort size is 4 and we want to specify three time intervals between these four consecutive patients, i.e. 7 units of time between the 1st and the 2nd patient, 5 units between the 2nd and the 3rd one, and finally 3 units between the 3rd and the 4th one, then, gap = list(c(7L, 5L, 3L)). Sometimes, we want that the interval only between the 1st and 2nd patient should be increased for the safety consideration and the rest time intervals should remain constant, regardless of what the cohort size is. Then, gap = list(c(7L, 3L)) and the the package will automatically repeat the last element of the vector for the remaining time intervals.

size

(integer)
a vector with the left bounds of the relevant cohort size intervals. This is used as follows. For instance, when we want to change the gap based on the cohort size, i.e. the time interval between the 1st and 2nd patient = 9 units of time and the rest time intervals are of 5 units of time when the cohort size is equal to or larger than 4. And the time interval between the 1st and 2nd patient = 7 units of time and the rest time intervals are 3 units of time when the cohort size is smaller than 4, then we specify both gap = list(c(7, 3), c(9, 5)) and size = c(0L, 4L). This means, the right bounds of the intervals are excluded from the interval, and the last interval goes from the last value to infinity.

follow

(count)
the period of time that each patient in the cohort needs to be followed before the next cohort opens.

follow_min

(count)
at least one patient in the cohort needs to be followed at the minimal follow up time.

Note

Typically, end users will not use the .DefaultSafetyWindowSize() function.

Examples

# Rule for having patient gap (7,3,3,3,...) for cohort size < 4, and
# patient gap (9,5,5,5...) for cohort size >= 4.
my_window_len <- SafetyWindowSize(
  gap = list(c(7, 3), c(9, 5)),
  size = c(1, 4),
  follow = 7,
  follow_min = 14
)