Create timing designs (static or adaptive) for use in simulated trial, such as sampling designs, target designs etc.

This function is used by the three functions create_sampling_design(), create_regimen_update_design() and create_target_design(), but is itself not intended for direct usage.

Usage

create_design(
  time = NULL,
  when = NULL,
  offset = NULL,
  scatter = NULL,
  at = NULL,
  anchor = c("dose", "day")
)

Arguments

time: a vector of numeric values. If no at values are specified, these will be used as the fixed sampling times in the simulated trial. If at values are supplied, the sampling times will be calculated adaptively during the trial. The at determine which dose or day is used as reference, and time will be relative to the specified at anchor.
when: character vector of same length as time (or single value) determining how to interpret the provided sampling time. If NULL will use the dose time as offset (default). Other options are: cmax or peak, which will use the end of infusion as the base for the time, or cmin or trough, which will use the time of next dose as the offset, or middle or cmid which will use the middle between the anchored dose and the next, or random which takes a random time point between the anchored dose and the next.
offset: offset from standardized PK moments specified in when, e.g. c(1, -1) with when = c("peak", "trough") to sample 1 hour after peak and 1 hour before trough.
scatter: optional random variation in time, specified as the standard deviation, e.g. scatter = 0.1 to allow for variation in sampling time with an SD of 0.1 hours. Only relevant for sampling times, not for regimen_update designs or target designs. Random variation does not protect for peaks or troughs becoming sampled during infusion or in previous / next dose. So value for scatter should be chosen appropriately and probably used in conjunction with approriate offset values.
at: numeric vector of the dose or day number to "anchor" the sampling times to. Vector needs to be of same length as time. If anchor is set to day, then the first dose in that day is used. If later doses in the day are preferred, the anchor can also be specified fractionally, e.g. 1.5 will use the time of the first dose in the second half of the 1st day.
anchor: either day or dose. Single value required, i.e. anchor types cannot be mixed.