- dtc
The --DTC date to impute
A character date is expected in a format like yyyy-mm-dd or
yyyy-mm-ddThh:mm:ss. Trailing components can be omitted and - is a
valid "missing" value for any component.
- Permitted values
a character date variable
- Default value
none
highest_imputation
Highest imputation level
The highest_imputation argument controls which components of the DTC
value are imputed if they are missing. All components up to the specified
level are imputed.
If a component at a higher level than the highest imputation level is
missing, NA_character_ is returned. For example, for highest_imputation = "D" "2020" results in NA_character_ because the month is missing.
If "n" is specified, no imputation is performed, i.e., if any component is
missing, NA_character_ is returned.
If "Y" is specified, date_imputation should be "first" or "last"
and min_dates or max_dates should be specified respectively. Otherwise,
NA_character_ is returned if the year component is missing.
- Permitted values
"Y" (year, highest level), "M" (month), "D"
(day), "h" (hour), "m" (minute), "s" (second), "n" (none, lowest
level)
Default value
"h"
date_imputation
The value to impute the day/month when a datepart is
missing.
A character value is expected.
If highest_imputation is "M", month and day can be
specified as "mm-dd": e.g. "06-15" for the 15th of June
When highest_imputation is "M" or "D", the following keywords are available:
"first", "mid", "last" to impute to the first/mid/last
day/month. If "mid" is specified, missing components are imputed as the
middle of the possible range:
If both month and day are missing, they are imputed as "06-30"
(middle of the year).
If only day is missing, it is imputed as "15" (middle of the month).
The year can not be specified; for imputing the year
"first" or "last" together with min_dates or max_dates argument can
be used (see examples).
- Permitted values
"first", "mid", "last", or user-defined
- Default value
"first"
time_imputation
The value to impute the time when a timepart is
missing.
A character value is expected, either as a
format with hour, min and sec specified as "hh:mm:ss": e.g. "00:00:00"
for the start of the day,
or as a keyword: "first","last" to impute to the start/end of a day.
The argument is ignored if highest_imputation = "n".
- Permitted values
"first", "last", or user-defined
- Default value
"first"
min_dates
Minimum dates
A list of dates is expected. It is ensured that the imputed date is not
before any of the specified dates, e.g., that the imputed adverse event start
date is not before the first treatment date. Only dates which are in the
range of possible dates of the dtc value are considered. The possible dates
are defined by the missing parts of the dtc date (see example below). This
ensures that the non-missing parts of the dtc date are not changed.
A date or date-time object is expected.
For example
impute_dtc_dtm(
"2020-11",
min_dates = list(
ymd_hms("2020-12-06T12:12:12"),
ymd_hms("2020-11-11T11:11:11")
),
highest_imputation = "M"
)
returns "2020-11-11T11:11:11" because the possible dates for "2020-11"
range from "2020-11-01T00:00:00" to "2020-11-30T23:59:59". Therefore
"2020-12-06T12:12:12" is ignored. Returning "2020-12-06T12:12:12" would
have changed the month although it is not missing (in the dtc date).
For date variables (not datetime) in the list the time is imputed to
"00:00:00". Specifying date variables makes sense only if the date is
imputed. If only time is imputed, date variables do not affect the result.
- Permitted values
a list of dates, e.g. list(ymd_hms("2021-07-01T04:03:01"), ymd_hms("2022-05-12T13:57:23"))
Default value
NULL
max_dates
Maximum dates
A list of dates is expected. It is ensured that the imputed date is not after
any of the specified dates, e.g., that the imputed date is not after the data
cut off date. Only dates which are in the range of possible dates are
considered. A date or date-time object is expected.
For date variables (not datetime) in the list the time is imputed to
"23:59:59". Specifying date variables makes sense only if the date is
imputed. If only time is imputed, date variables do not affect the result.
- Permitted values
a list of dates, e.g. list(ymd_hms("2021-07-01T04:03:01"), ymd_hms("2022-05-12T13:57:23"))
Default value
NULL
preserve
Preserve lower level date/time part when higher order part
is missing, e.g. preserve day if month is missing or
preserve minute when hour is missing.
For example "2019---07" would return "2019-06-07 if preserve = TRUE
(and date_imputation = "mid").
- Permitted values
"TRUE", "FALSE"
Default value
FALSE