Alternative imputation rule set 1

Usage

imputation_rules_1

Format

A list of the following functions:

admin_pre_expansion()
admin_post_expansion()
obs_raw()
obs_final()

Details

This imputation rule set includes the following imputation steps:

Treatment administrations:

Filter administrations to the cut-off date.
Impute missing EXENDTC values in the last administration episode to the cut-off date.
Impute missing (non-last) EXENDTC values to the day before the start of the subsequent administration episode.
Remove records where EXENDTC is before EXSTDTC.
Expand administration episodes from the EX domain between EXSTDTC and EXENDTC.
For each administration event, take the administration time from PCRFTDTC of the PC domain if there are related pharmacokinetic observations. The name of the PK analyte (PCTESTCD) that corresponds with the administered treatment (EXTRT) must be specified by the 'pctestcd' to add_administration().
For administration events that have associated PK observations but PCRFTDTC is not defined, back-calculate the administration time, if possible, from the PK observations based on their nominal time (PCTPT).
In cases where the administration time back-calculated from NTIME is more than 10 min different from the administration time taken from the EXSTDTC, it is assumed that the NTIME-derived administration time is more precise than that from EXSTDTC and is prioritized.
After the above imputations, the administration time is carried forward for subsequent administration events until the next imputed time.

Observations

Pharmacokinetic observations below the level of quantification (BLQ) are set to PCLLOQ / 2.
For all predose observations, TAFD is set to zero.

Creating custom imputation rules

You can create your own imputation rule set by providing a named list with any combination of the four function slots: admin_pre_expansion, admin_post_expansion, obs_raw, and obs_final. Each function receives specific arguments depending on its slot.