Methods for imputation of data with PKNCA

Usage

PKNCA_impute_method_start_conc0(conc, time, start = 0, ..., options = list())

PKNCA_impute_method_start_cmin(conc, time, start, end, ..., options = list())

PKNCA_impute_method_start_predose(
  conc,
  time,
  start,
  end,
  conc.group,
  time.group,
  ...,
  max_shift = NA_real_,
  options = list()
)

PKNCA_impute_method_start_predose_conc0(
  conc,
  time,
  start,
  end,
  conc.group,
  time.group,
  ...,
  max_shift = NA_real_,
  options = list()
)

PKNCA_impute_method_end_conc_drop(conc, time, end, ..., options = list())

Arguments

conc: Measured concentrations
time: Time of the measurement of the concentrations
start: The start time of the interval
...: ignored
options: List of changes to the default PKNCA options (see PKNCA.options())
end: The end time of the interval
conc.group: All concentrations measured for the group
time.group: Time of all concentrations measured for the group
max_shift: The maximum amount of time to shift a concentration forward (defaults to 5% of the interval duration, i.e. 0.05*(end - start), if is.finite(end), and when is.infinite(end), defaults to 5% of the time from start to max(time))

Value

A data.frame with one column named conc with imputed concentrations and one column named time with the times.

Functions

PKNCA_impute_method_start_conc0(): Set the concentration at the start time to 0, even if a nonzero concentration exists at that time (usually used with single-dose data). Forcing the start concentration to zero is intentional: an existing start-time value is replaced with 0, including a nonzero predose measurement shifted to the start time by start_predose, so the imputation chain "start_predose,start_conc0" gives the same result as "start_conc0" alone. To carry a predose measurement to the start time, use start_predose without start_conc0. When no observation exists at the start time, a new row with a concentration of 0 is added.
PKNCA_impute_method_start_cmin(): Add a new concentration of the minimum during the interval at the start time (usually used with multiple-dose data)
PKNCA_impute_method_start_predose(): Shift a predose concentration to become the time zero concentration (only if a time zero concentration does not exist). The most recent predose sample with a measured concentration is shifted; samples with a missing concentration are skipped.
PKNCA_impute_method_start_predose_conc0(): Use a predose concentration as the start concentration when one is available and 0 when it is not. A concentration measured at the start time is kept as-is, which is what distinguishes this from start_conc0: a measured concentration at the time of an intravenous bolus dose is the C0 for that dose, and start_conc0 would replace it with 0. The chain "start_predose,start_conc0" cannot express this, because start_conc0 overwrites whatever start_predose shifted.
PKNCA_impute_method_end_conc_drop(): Drop a concentration measured exactly at the end of the interval, if one is present (usually used with multiple-dose data when a point at the interval boundary belongs to the next dose, e.g. an imputed C0)