Derives duration between two dates, specified by the variables present in input dataset e.g., duration of adverse events, relative day, age, ...
derive_vars_duration(
dataset,
new_var,
new_var_unit = NULL,
start_date,
end_date,
in_unit = "days",
out_unit = "DAYS",
floor_in = TRUE,
add_one = TRUE,
trunc_out = FALSE,
type = "duration"
)Input dataset
The variables specified by the start_date and end_date arguments are expected to be in the dataset.
none
Name of variable to create
none
Name of the unit variable If the parameter is not specified, no variable for the unit is created.
NULL
The start date
A date or date-time object is expected.
Refer to derive_vars_dt() to impute and derive a date from a date
character vector to a date object.
Refer to convert_dtc_to_dt() to obtain a vector of imputed dates.
none
The end date
A date or date-time object is expected.
Refer to derive_vars_dt() to impute and derive a date from a date
character vector to a date object.
Refer to convert_dtc_to_dt() to obtain a vector of imputed dates.
none
Input unit
See floor_in and add_one parameter for details.
Permitted Values (case-insensitive):
For years: "year", "years", "yr", "yrs", "y"
For months: "month", "months", "mo", "mos"
For days: "day", "days", "d"
For hours: "hour", "hours", "hr", "hrs", "h"
For minutes: "minute", "minutes", "min", "mins"
For seconds: "second", "seconds", "sec", "secs", "s"
"days"
Output unit
The duration is derived in the specified unit
Permitted Values (case-insensitive):
For years: "year", "years", "yr", "yrs", "y"
For months: "month", "months", "mo", "mos"
For weeks: "week", "weeks", "wk", "wks", "w"
For days: "day", "days", "d"
For hours: "hour", "hours", "hr", "hrs", "h"
For minutes: "minute", "minutes", "min", "mins"
For seconds: "second", "seconds", "sec", "secs", "s"
"days"
Round down input dates?
The input dates are round down with respect to the input unit, e.g., if the input unit is 'days', the time of the input dates is ignored.
TRUE, FALSE
TRUE
Add one input unit?
If the duration is non-negative, one input unit is added. i.e., the duration can not be zero.
TRUE, FALSE
TRUE
Return integer part
The fractional part of the duration (in output unit) is removed, i.e., the integer part is returned.
TRUE, FALSE
FALSE
lubridate duration type.
See below for details.
"duration", "interval"
"duration"
The input dataset with the duration and unit variable added
The duration is derived as time from start to end date in the specified output unit. If the end date is before the start date, the duration is negative. The start and end date variable must be present in the specified input dataset.
The lubridate package calculates two types of spans between two dates: duration and interval. While these calculations are largely the same, when the unit of the time period is month or year the result can be slightly different.
The difference arises from the ambiguity in the length of "1 month" or
"1 year".
Months may have 31, 30, 28, or 29 days, and years are 365 days and 366 during leap years.
Durations and intervals help solve the ambiguity in these measures.
The interval between 2000-02-01 and 2000-03-01 is 1 (i.e. one month).
The duration between these two dates is 0.95, which accounts for the fact
that the year 2000 is a leap year, February has 29 days, and the average month
length is 30.4375, i.e. 29 / 30.4375 = 0.95.
For additional details, review the lubridate time span reference page.
Date/Time Derivation Functions that returns variable appended to dataset:
derive_var_trtdurd(),
derive_vars_dt(),
derive_vars_dtm(),
derive_vars_dtm_to_dt(),
derive_vars_dtm_to_tm(),
derive_vars_dy()
library(lubridate)
library(tibble)
# Derive age in years
data <- tribble(
~USUBJID, ~BRTHDT, ~RANDDT,
"P01", ymd("1984-09-06"), ymd("2020-02-24"),
"P02", ymd("1985-01-01"), NA,
"P03", NA, ymd("2021-03-10"),
"P04", NA, NA
)
derive_vars_duration(data,
new_var = AAGE,
new_var_unit = AAGEU,
start_date = BRTHDT,
end_date = RANDDT,
out_unit = "years",
add_one = FALSE,
trunc_out = TRUE
)
#> # A tibble: 4 × 5
#> USUBJID BRTHDT RANDDT AAGE AAGEU
#> <chr> <date> <date> <dbl> <chr>
#> 1 P01 1984-09-06 2020-02-24 35 years
#> 2 P02 1985-01-01 NA NA NA
#> 3 P03 NA 2021-03-10 NA NA
#> 4 P04 NA NA NA NA
# Derive adverse event duration in days
data <- tribble(
~USUBJID, ~ASTDT, ~AENDT,
"P01", ymd("2021-03-05"), ymd("2021-03-02"),
"P02", ymd("2019-09-18"), ymd("2019-09-18"),
"P03", ymd("1985-01-01"), NA,
"P04", NA, NA
)
derive_vars_duration(data,
new_var = ADURN,
new_var_unit = ADURU,
start_date = ASTDT,
end_date = AENDT,
out_unit = "days"
)
#> # A tibble: 4 × 5
#> USUBJID ASTDT AENDT ADURN ADURU
#> <chr> <date> <date> <dbl> <chr>
#> 1 P01 2021-03-05 2021-03-02 -3 days
#> 2 P02 2019-09-18 2019-09-18 1 days
#> 3 P03 1985-01-01 NA NA NA
#> 4 P04 NA NA NA NA
# Derive adverse event duration in minutes
data <- tribble(
~USUBJID, ~ADTM, ~TRTSDTM,
"P01", ymd_hms("2019-08-09T04:30:56"), ymd_hms("2019-08-09T05:00:00"),
"P02", ymd_hms("2019-11-11T10:30:00"), ymd_hms("2019-11-11T11:30:00"),
"P03", ymd_hms("2019-11-11T00:00:00"), ymd_hms("2019-11-11T04:00:00"),
"P04", NA, ymd_hms("2019-11-11T12:34:56"),
)
derive_vars_duration(data,
new_var = ADURN,
new_var_unit = ADURU,
start_date = ADTM,
end_date = TRTSDTM,
in_unit = "minutes",
out_unit = "minutes",
add_one = FALSE
)
#> # A tibble: 4 × 5
#> USUBJID ADTM TRTSDTM ADURN ADURU
#> <chr> <dttm> <dttm> <dbl> <chr>
#> 1 P01 2019-08-09 04:30:56 2019-08-09 05:00:00 30 minutes
#> 2 P02 2019-11-11 10:30:00 2019-11-11 11:30:00 60 minutes
#> 3 P03 2019-11-11 00:00:00 2019-11-11 04:00:00 240 minutes
#> 4 P04 NA 2019-11-11 12:34:56 NA NA
# Derive adverse event start time since last dose in hours
data <- tribble(
~USUBJID, ~ASTDTM, ~LDOSEDTM,
"P01", ymd_hms("2019-08-09T04:30:56"), ymd_hms("2019-08-08T10:05:00"),
"P02", ymd_hms("2019-11-11T23:59:59"), ymd_hms("2019-10-11T11:37:00"),
"P03", ymd_hms("2019-11-11T00:00:00"), ymd_hms("2019-11-10T23:59:59"),
"P04", ymd_hms("2019-11-11T12:34:56"), NA,
"P05", NA, ymd_hms("2019-09-28T12:34:56")
)
derive_vars_duration(
data,
new_var = LDRELTM,
new_var_unit = LDRELTMU,
start_date = LDOSEDTM,
end_date = ASTDTM,
in_unit = "hours",
out_unit = "hours",
add_one = FALSE
)
#> # A tibble: 5 × 5
#> USUBJID ASTDTM LDOSEDTM LDRELTM LDRELTMU
#> <chr> <dttm> <dttm> <dbl> <chr>
#> 1 P01 2019-08-09 04:30:56 2019-08-08 10:05:00 18 hours
#> 2 P02 2019-11-11 23:59:59 2019-10-11 11:37:00 756 hours
#> 3 P03 2019-11-11 00:00:00 2019-11-10 23:59:59 1 hours
#> 4 P04 2019-11-11 12:34:56 NA NA NA
#> 5 P05 NA 2019-09-28 12:34:56 NA NA