Add a time-to-event parameter to the input dataset.
Usage
derive_param_tte(
dataset = NULL,
dataset_adsl,
source_datasets,
by_vars = NULL,
start_date = TRTSDT,
event_conditions,
censor_conditions,
create_datetime = FALSE,
set_values_to,
subject_keys = get_admiral_option("subject_keys"),
check_type = "warning"
)
Arguments
- dataset
Input dataset
PARAMCD
is expected.- Permitted values
a dataset, i.e., a
data.frame
or tibble- Default value
NULL
- dataset_adsl
ADSL input dataset
The variables specified for
start_date
, andsubject_keys
are expected.- Permitted values
a dataset, i.e., a
data.frame
or tibble- Default value
none
- source_datasets
Source datasets
A named list of datasets is expected. The
dataset_name
field oftte_source()
refers to the dataset provided in the list.- Permitted values
named list of datasets, e.g.,
list(adsl = adsl, ae = ae)
- Default value
none
- by_vars
By variables
If the parameter is specified, separate time to event parameters are derived for each by group.
The by variables must be in at least one of the source datasets. Each source dataset must contain either all by variables or none of the by variables.
The by variables are not included in the output dataset.
- Permitted values
list of variables created by
exprs()
, e.g.,exprs(USUBJID, VISIT)
- Default value
NULL
- start_date
Time to event origin date
The variable
STARTDT
is set to the specified date. The value is taken from the ADSL dataset.If the event or censoring date is before the origin date,
ADT
is set to the origin date.- Permitted values
a date variable
- Default value
TRTSDT
- event_conditions
Sources and conditions defining events
A list of
event_source()
objects is expected.- Permitted values
a list of source objects, e.g.,
list(pd, death)
- Default value
none
- censor_conditions
Sources and conditions defining censorings
A list of
censor_source()
objects is expected.- Permitted values
a list of source objects, e.g.,
list(pd, death)
- Default value
none
- create_datetime
Create datetime variables?
If set to
TRUE
, variablesADTM
andSTARTDTM
are created. Otherwise, variablesADT
andSTARTDT
are created.- Default value
FALSE
- set_values_to
Variables to set
A named list returned by
exprs()
defining the variables to be set for the new parameter, e.g.exprs(PARAMCD = "OS", PARAM = "Overall Survival")
is expected. The values must be symbols, character strings, numeric values, expressions, orNA
.- Default value
none
- subject_keys
Variables to uniquely identify a subject
A list of symbols created using
exprs()
is expected.- Permitted values
list of variables created by
exprs()
, e.g.,exprs(USUBJID, VISIT)
- Default value
get_admiral_option("subject_keys")
- check_type
Check uniqueness
If
"warning"
,"message"
, or"error"
is specified, the specified message is issued if the observations of the source datasets are not unique with respect to the by variables and the date and order specified in theevent_source()
andcensor_source()
objects.- Permitted values
"none"
,"message"
,"warning"
,"error"
- Default value
"warning"
Details
The following steps are performed to create the observations of the new parameter:
Deriving the events:
For each event source dataset the observations as specified by the
filter
element are selected. Then for each subject the first observation (with respect todate
andorder
) is selected.The
ADT
variable is set to the variable specified by thedate
element. If the date variable is a datetime variable, only the datepart is copied.The
CNSR
variable is added and set to thecensor
element.The variables specified by the
set_values_to
element are added.The selected observations of all event source datasets are combined into a single dataset.
For each subject the first observation (with respect to the
ADT
/ADTM
variable) from the single dataset is selected. If there is more than one event with the same date, the first event with respect to the order of events inevent_conditions
is selected.
Deriving the censoring observations:
For each censoring source dataset the observations as specified by the
filter
element are selected. Then for each subject the last observation (with respect todate
andorder
) is selected.The
ADT
variable is set to the variable specified by thedate
element. If the date variable is a datetime variable, only the datepart is copied.The
CNSR
variable is added and set to thecensor
element.The variables specified by the
set_values_to
element are added.The selected observations of all censoring source datasets are combined into a single dataset.
For each subject the last observation (with respect to the
ADT
/ADTM
variable) from the single dataset is selected. If there is more than one censoring with the same date, the last censoring with respect to the order of censorings incensor_conditions
is selected.
For each subject (as defined by the subject_keys
parameter) an
observation is selected. If an event is available, the event observation is
selected. Otherwise the censoring observation is selected.
Finally:
The variable specified for
start_date
is joined from the ADSL dataset. Only subjects in both datasets are kept, i.e., subjects with both an event or censoring and an observation indataset_adsl
.The variables as defined by the
set_values_to
parameter are added.The
ADT
/ADTM
variable is set to the maximum ofADT
/ADTM
andSTARTDT
/STARTDTM
(depending on thecreate_datetime
parameter).The new observations are added to the output dataset.
Examples
Add a basic time to event parameter
For each subject the time to first adverse event should be created as a parameter.
The event source object is created using
event_source()
and the date is set to adverse event start date.The censor source object is created using
censor_source()
and the date is set to end of study date.The event and censor source objects are then passed to
derive_param_tte()
to derive the time to event parameter with the provided parameter descriptions (PARAMCD
andPARAM
).Note the values of the censor variable (
CNSR
) that are derived below, where the first subject has an event and the second does not.
library(tibble)
library(dplyr, warn.conflicts = FALSE)
library(lubridate, warn.conflicts = FALSE)
adsl <- tribble(
~USUBJID, ~TRTSDT, ~EOSDT, ~NEWDRGDT,
"01", ymd("2020-12-06"), ymd("2021-03-06"), NA,
"02", ymd("2021-01-16"), ymd("2021-02-03"), ymd("2021-01-03")
) %>%
mutate(STUDYID = "AB42")
adae <- tribble(
~USUBJID, ~ASTDT, ~AESEQ, ~AEDECOD,
"01", ymd("2021-01-03"), 1, "Flu",
"01", ymd("2021-03-04"), 2, "Cough",
"01", ymd("2021-03-05"), 3, "Cough"
) %>%
mutate(STUDYID = "AB42")
ttae <- event_source(
dataset_name = "adae",
date = ASTDT,
set_values_to = exprs(
EVNTDESC = "AE",
SRCDOM = "ADAE",
SRCVAR = "ASTDT",
SRCSEQ = AESEQ
)
)
eos <- censor_source(
dataset_name = "adsl",
date = EOSDT,
set_values_to = exprs(
EVNTDESC = "END OF STUDY",
SRCDOM = "ADSL",
SRCVAR = "EOSDT"
)
)
derive_param_tte(
dataset_adsl = adsl,
event_conditions = list(ttae),
censor_conditions = list(eos),
source_datasets = list(adsl = adsl, adae = adae),
set_values_to = exprs(
PARAMCD = "TTAE",
PARAM = "Time to First Adverse Event"
)
) %>%
select(USUBJID, STARTDT, PARAMCD, PARAM, ADT, CNSR, SRCSEQ)
#> # A tibble: 2 × 7
#> USUBJID STARTDT PARAMCD PARAM ADT CNSR SRCSEQ
#> <chr> <date> <chr> <chr> <date> <int> <dbl>
#> 1 01 2020-12-06 TTAE Time to First Adverse Event 2021-01-03 0 1
#> 2 02 2021-01-16 TTAE Time to First Adverse Event 2021-02-03 1 NA
Adding a by variable (by_vars
)
By variables can be added using the by_vars
argument, e.g., now for
each subject the time to first occurrence of each adverse event preferred
term (AEDECOD
) should be created as parameters.
derive_param_tte(
dataset_adsl = adsl,
by_vars = exprs(AEDECOD),
event_conditions = list(ttae),
censor_conditions = list(eos),
source_datasets = list(adsl = adsl, adae = adae),
set_values_to = exprs(
PARAMCD = paste0("TTAE", as.numeric(as.factor(AEDECOD))),
PARAM = paste("Time to First", AEDECOD, "Adverse Event")
)
) %>%
select(USUBJID, STARTDT, PARAMCD, PARAM, ADT, CNSR, SRCSEQ)
#> # A tibble: 4 × 7
#> USUBJID STARTDT PARAMCD PARAM ADT CNSR SRCSEQ
#> <chr> <date> <chr> <chr> <date> <int> <dbl>
#> 1 01 2020-12-06 TTAE1 Time to First Cough Advers… 2021-03-04 0 2
#> 2 01 2020-12-06 TTAE2 Time to First Flu Adverse … 2021-01-03 0 1
#> 3 02 2021-01-16 TTAE1 Time to First Cough Advers… 2021-02-03 1 NA
#> 4 02 2021-01-16 TTAE2 Time to First Flu Adverse … 2021-02-03 1 NA
Handling duplicates (check_type
)
The source records are checked regarding duplicates with respect to the
by variables and the date and order specified in the source objects.
By default, a warning is issued if any duplicates are found.
Note here how after creating a new adverse event dataset containing a
duplicate date for "Cough"
, it was then passed to the function using the
source_datasets
argument - where you see below adae = adae_dup
.
adae_dup <- tribble(
~USUBJID, ~ASTDT, ~AESEQ, ~AEDECOD, ~AESER,
"01", ymd("2021-01-03"), 1, "Flu", "Y",
"01", ymd("2021-03-04"), 2, "Cough", "N",
"01", ymd("2021-03-04"), 3, "Cough", "Y"
) %>%
mutate(STUDYID = "AB42")
derive_param_tte(
dataset_adsl = adsl,
by_vars = exprs(AEDECOD),
start_date = TRTSDT,
source_datasets = list(adsl = adsl, adae = adae_dup),
event_conditions = list(ttae),
censor_conditions = list(eos),
set_values_to = exprs(
PARAMCD = paste0("TTAE", as.numeric(as.factor(AEDECOD))),
PARAM = paste("Time to First", AEDECOD, "Adverse Event")
)
)
#> # A tibble: 4 × 11
#> USUBJID STUDYID EVNTDESC SRCDOM SRCVAR SRCSEQ CNSR ADT STARTDT
#> <chr> <chr> <chr> <chr> <chr> <dbl> <int> <date> <date>
#> 1 01 AB42 AE ADAE ASTDT 2 0 2021-03-04 2020-12-06
#> 2 01 AB42 AE ADAE ASTDT 1 0 2021-01-03 2020-12-06
#> 3 02 AB42 END OF STUDY ADSL EOSDT NA 1 2021-02-03 2021-01-16
#> 4 02 AB42 END OF STUDY ADSL EOSDT NA 1 2021-02-03 2021-01-16
#> # ℹ 2 more variables: PARAMCD <chr>, PARAM <chr>
#> Warning: Dataset "adae" contains duplicate records with respect to `STUDYID`, `USUBJID`,
#> `AEDECOD`, and `ASTDT`
#> ℹ Run `admiral::get_duplicates_dataset()` to access the duplicate records
For investigating the issue, the dataset of the duplicate source records
can be obtained by calling get_duplicates_dataset()
:
get_duplicates_dataset()
#> Duplicate records with respect to `STUDYID`, `USUBJID`, `AEDECOD`, and `ASTDT`.
#> # A tibble: 2 × 6
#> STUDYID USUBJID AEDECOD ASTDT AESEQ AESER
#> * <chr> <chr> <chr> <date> <dbl> <chr>
#> 1 AB42 01 Cough 2021-03-04 2 N
#> 2 AB42 01 Cough 2021-03-04 3 Y
Common options to solve the issue:
Restricting the source records by specifying/updating the
filter
argument in theevent_source()
/censor_source()
calls.Specifying additional variables for
order
in theevent_source()
/censor_source()
calls.Setting
check_type = "none"
in thederive_param_tte()
call to ignore any duplicates.
In this example it does not have significant impact which record is chosen as
the dates are the same so the time to event derivation will be the same, but
it does impact SRCSEQ
in the output dataset, so here the second option is
used.
Note here how you can also define source objects from within the derive_param_tte()
function call itself.
derive_param_tte(
dataset_adsl = adsl,
by_vars = exprs(AEDECOD),
start_date = TRTSDT,
source_datasets = list(adsl = adsl, adae = adae_dup),
event_conditions = list(event_source(
dataset_name = "adae",
date = ASTDT,
set_values_to = exprs(
EVNTDESC = "AE",
SRCDOM = "ADAE",
SRCVAR = "ASTDT",
SRCSEQ = AESEQ
),
order = exprs(AESEQ)
)),
censor_conditions = list(eos),
set_values_to = exprs(
PARAMCD = paste0("TTAE", as.numeric(as.factor(AEDECOD))),
PARAM = paste("Time to First", AEDECOD, "Adverse Event")
)
) %>%
select(USUBJID, STARTDT, PARAMCD, PARAM, ADT, CNSR, SRCSEQ)
#> # A tibble: 4 × 7
#> USUBJID STARTDT PARAMCD PARAM ADT CNSR SRCSEQ
#> <chr> <date> <chr> <chr> <date> <int> <dbl>
#> 1 01 2020-12-06 TTAE1 Time to First Cough Advers… 2021-03-04 0 2
#> 2 01 2020-12-06 TTAE2 Time to First Flu Adverse … 2021-01-03 0 1
#> 3 02 2021-01-16 TTAE1 Time to First Cough Advers… 2021-02-03 1 NA
#> 4 02 2021-01-16 TTAE2 Time to First Flu Adverse … 2021-02-03 1 NA
Filtering source records (filter
)
The first option from above could have been achieved using filter
, for
example here only using serious adverse events.
derive_param_tte(
dataset_adsl = adsl,
by_vars = exprs(AEDECOD),
start_date = TRTSDT,
source_datasets = list(adsl = adsl, adae = adae_dup),
event_conditions = list(event_source(
dataset_name = "adae",
filter = AESER == "Y",
date = ASTDT,
set_values_to = exprs(
EVNTDESC = "Serious AE",
SRCDOM = "ADAE",
SRCVAR = "ASTDT",
SRCSEQ = AESEQ
)
)),
censor_conditions = list(eos),
set_values_to = exprs(
PARAMCD = paste0("TTSAE", as.numeric(as.factor(AEDECOD))),
PARAM = paste("Time to First Serious", AEDECOD, "Adverse Event")
)
) %>%
select(USUBJID, STARTDT, PARAMCD, PARAM, ADT, CNSR, SRCSEQ)
#> # A tibble: 4 × 7
#> USUBJID STARTDT PARAMCD PARAM ADT CNSR SRCSEQ
#> <chr> <date> <chr> <chr> <date> <int> <dbl>
#> 1 01 2020-12-06 TTSAE1 Time to First Serious Coug… 2021-03-04 0 3
#> 2 01 2020-12-06 TTSAE2 Time to First Serious Flu … 2021-01-03 0 1
#> 3 02 2021-01-16 TTSAE1 Time to First Serious Coug… 2021-02-03 1 NA
#> 4 02 2021-01-16 TTSAE2 Time to First Serious Flu … 2021-02-03 1 NA
Using multiple event/censor conditions (event_conditions
/censor_conditions
)
In the above examples, we only have a single event and single censor
condition. Here, we now consider multiple conditions for each passed using
event_conditions
and censor_conditions
.
For the event we are going to use first AE and additionally check a lab condition, and for the censor we'll add in treatment start date in case end of study date was ever missing.
adlb <- tribble(
~USUBJID, ~ADT, ~PARAMCD, ~ANRIND,
"01", ymd("2020-12-22"), "HGB", "LOW"
) %>%
mutate(STUDYID = "AB42")
low_hgb <- event_source(
dataset_name = "adlb",
filter = PARAMCD == "HGB" & ANRIND == "LOW",
date = ADT,
set_values_to = exprs(
EVNTDESC = "POSSIBLE ANEMIA",
SRCDOM = "ADLB",
SRCVAR = "ADT"
)
)
trt_start <- censor_source(
dataset_name = "adsl",
date = TRTSDT,
set_values_to = exprs(
EVNTDESC = "TREATMENT START",
SRCDOM = "ADSL",
SRCVAR = "TRTSDT"
)
)
derive_param_tte(
dataset_adsl = adsl,
event_conditions = list(ttae, low_hgb),
censor_conditions = list(eos, trt_start),
source_datasets = list(adsl = adsl, adae = adae, adlb = adlb),
set_values_to = exprs(
PARAMCD = "TTAELB",
PARAM = "Time to First Adverse Event or Possible Anemia (Labs)"
)
) %>%
select(USUBJID, STARTDT, PARAMCD, PARAM, ADT, CNSR, SRCSEQ)
#> # A tibble: 2 × 7
#> USUBJID STARTDT PARAMCD PARAM ADT CNSR SRCSEQ
#> <chr> <date> <chr> <chr> <date> <int> <dbl>
#> 1 01 2020-12-06 TTAELB Time to First Adverse Even… 2020-12-22 0 NA
#> 2 02 2021-01-16 TTAELB Time to First Adverse Even… 2021-02-03 1 NA
Note above how the earliest event date is always taken and the latest censor date.
Using different censor values (censor
) and censoring at earliest
occurring censor condition
Within censor_source()
the value used to denote a censor can be
changed from the default of 1
.
In this example an extra censor is used for new drug date with the value of 2
.
newdrug <- censor_source(
dataset_name = "adsl",
date = NEWDRGDT,
censor = 2,
set_values_to = exprs(
EVNTDESC = "NEW DRUG RECEIVED",
SRCDOM = "ADSL",
SRCVAR = "NEWDRGDT"
)
)
derive_param_tte(
dataset_adsl = adsl,
by_vars = exprs(AEDECOD),
event_conditions = list(ttae),
censor_conditions = list(eos, newdrug),
source_datasets = list(adsl = adsl, adae = adae),
set_values_to = exprs(
PARAMCD = paste0("TTAE", as.numeric(as.factor(AEDECOD))),
PARAM = paste("Time to First", AEDECOD, "Adverse Event")
)
) %>%
select(USUBJID, STARTDT, PARAMCD, PARAM, ADT, CNSR, SRCSEQ)
#> # A tibble: 4 × 7
#> USUBJID STARTDT PARAMCD PARAM ADT CNSR SRCSEQ
#> <chr> <date> <chr> <chr> <date> <int> <dbl>
#> 1 01 2020-12-06 TTAE1 Time to First Cough Advers… 2021-03-04 0 2
#> 2 01 2020-12-06 TTAE2 Time to First Flu Adverse … 2021-01-03 0 1
#> 3 02 2021-01-16 TTAE1 Time to First Cough Advers… 2021-02-03 1 NA
#> 4 02 2021-01-16 TTAE2 Time to First Flu Adverse … 2021-02-03 1 NA
In this case the results are still the same, because as explained in the above example the latest censor condition is always taken for those without an event. For the second subject this is still the end of study date.
So, if we wanted to instead censor here at the new drug date if subject
has one, then we would need to again use the filter
argument, but this
time for a new end of study censor source object.
eos_nonewdrug <- censor_source(
dataset_name = "adsl",
filter = is.na(NEWDRGDT),
date = EOSDT,
set_values_to = exprs(
EVNTDESC = "END OF STUDY",
SRCDOM = "ADSL",
SRCVAR = "EOSDT"
)
)
derive_param_tte(
dataset_adsl = adsl,
by_vars = exprs(AEDECOD),
event_conditions = list(ttae),
censor_conditions = list(eos_nonewdrug, newdrug),
source_datasets = list(adsl = adsl, adae = adae),
set_values_to = exprs(
PARAMCD = paste0("TTAE", as.numeric(as.factor(AEDECOD))),
PARAM = paste("Time to First", AEDECOD, "Adverse Event")
)
) %>%
select(USUBJID, STARTDT, PARAMCD, PARAM, ADT, CNSR, SRCSEQ)
#> # A tibble: 4 × 7
#> USUBJID STARTDT PARAMCD PARAM ADT CNSR SRCSEQ
#> <chr> <date> <chr> <chr> <date> <int> <dbl>
#> 1 01 2020-12-06 TTAE1 Time to First Cough Advers… 2021-03-04 0 2
#> 2 01 2020-12-06 TTAE2 Time to First Flu Adverse … 2021-01-03 0 1
#> 3 02 2021-01-16 TTAE1 Time to First Cough Advers… 2021-01-16 2 NA
#> 4 02 2021-01-16 TTAE2 Time to First Flu Adverse … 2021-01-16 2 NA
Overall survival time to event parameter
In oncology trials, this is commonly derived as time from randomization date to death. For those without event, they are censored at the last date they are known to be alive.
The start date is set using
start_date
argument, now that we need to use different to the default.In this example, datetime was needed, which can be achieved by setting
create_datetime
argument toTRUE
.
adsl <- tribble(
~USUBJID, ~RANDDTM, ~LSALVDTM, ~DTHDTM, ~DTHFL,
"01", ymd_hms("2020-10-03 00:00:00"), ymd_hms("2022-12-15 23:59:59"), NA, NA,
"02", ymd_hms("2021-01-23 00:00:00"), ymd_hms("2021-02-03 19:45:59"), ymd_hms("2021-02-03 19:45:59"), "Y"
) %>%
mutate(STUDYID = "AB42")
# derive overall survival parameter
death <- event_source(
dataset_name = "adsl",
filter = DTHFL == "Y",
date = DTHDTM,
set_values_to = exprs(
EVNTDESC = "DEATH",
SRCDOM = "ADSL",
SRCVAR = "DTHDTM"
)
)
last_alive <- censor_source(
dataset_name = "adsl",
date = LSALVDTM,
set_values_to = exprs(
EVNTDESC = "LAST DATE KNOWN ALIVE",
SRCDOM = "ADSL",
SRCVAR = "LSALVDTM"
)
)
derive_param_tte(
dataset_adsl = adsl,
start_date = RANDDTM,
event_conditions = list(death),
censor_conditions = list(last_alive),
create_datetime = TRUE,
source_datasets = list(adsl = adsl),
set_values_to = exprs(
PARAMCD = "OS",
PARAM = "Overall Survival"
)
) %>%
select(USUBJID, STARTDTM, PARAMCD, PARAM, ADTM, CNSR)
#> # A tibble: 2 × 6
#> USUBJID STARTDTM PARAMCD PARAM ADTM CNSR
#> <chr> <dttm> <chr> <chr> <dttm> <int>
#> 1 01 2020-10-03 00:00:00 OS Overall Survival 2022-12-15 23:59:59 1
#> 2 02 2021-01-23 00:00:00 OS Overall Survival 2021-02-03 19:45:59 0
Duration of response time to event parameter
In oncology trials, this is commonly derived as time from response until
progression or death, or if neither have occurred then censor at last tumor
assessment visit date. It is only relevant for subjects with a response.
Note how only observations for subjects in dataset_adsl
have the new
parameter created, so see below how this is filtered only on responders.
adsl_resp <- tribble(
~USUBJID, ~DTHFL, ~DTHDT, ~RSPDT,
"01", "Y", ymd("2021-06-12"), ymd("2021-03-04"),
"02", "N", NA, NA,
"03", "Y", ymd("2021-08-21"), NA,
"04", "N", NA, ymd("2021-04-14")
) %>%
mutate(STUDYID = "AB42")
adrs <- tribble(
~USUBJID, ~AVALC, ~ADT, ~ASEQ,
"01", "SD", ymd("2021-01-03"), 1,
"01", "PR", ymd("2021-03-04"), 2,
"01", "PD", ymd("2021-05-05"), 3,
"02", "PD", ymd("2021-02-03"), 1,
"04", "SD", ymd("2021-02-13"), 1,
"04", "PR", ymd("2021-04-14"), 2,
"04", "CR", ymd("2021-05-15"), 3
) %>%
mutate(STUDYID = "AB42", PARAMCD = "OVR")
pd <- event_source(
dataset_name = "adrs",
filter = AVALC == "PD",
date = ADT,
set_values_to = exprs(
EVENTDESC = "PD",
SRCDOM = "ADRS",
SRCVAR = "ADTM",
SRCSEQ = ASEQ
)
)
death <- event_source(
dataset_name = "adsl",
filter = DTHFL == "Y",
date = DTHDT,
set_values_to = exprs(
EVENTDESC = "DEATH",
SRCDOM = "ADSL",
SRCVAR = "DTHDT"
)
)
last_visit <- censor_source(
dataset_name = "adrs",
date = ADT,
set_values_to = exprs(
EVENTDESC = "LAST TUMOR ASSESSMENT",
SRCDOM = "ADRS",
SRCVAR = "ADTM",
SRCSEQ = ASEQ
)
)
derive_param_tte(
dataset_adsl = filter(adsl_resp, !is.na(RSPDT)),
start_date = RSPDT,
event_conditions = list(pd, death),
censor_conditions = list(last_visit),
source_datasets = list(adsl = adsl_resp, adrs = adrs),
set_values_to = exprs(
PARAMCD = "DURRSP",
PARAM = "Duration of Response"
)
) %>%
select(USUBJID, STARTDT, PARAMCD, PARAM, ADT, CNSR, SRCSEQ)
#> # A tibble: 2 × 7
#> USUBJID STARTDT PARAMCD PARAM ADT CNSR SRCSEQ
#> <chr> <date> <chr> <chr> <date> <int> <dbl>
#> 1 01 2021-03-04 DURRSP Duration of Response 2021-05-05 0 3
#> 2 04 2021-04-14 DURRSP Duration of Response 2021-05-15 1 3
Further examples
Further example usages of this function can be found in the Time-to-Event vignette.