calc_study_duration {beastt} | R Documentation |
Calculate the Analysis Time Based on a Target Number of Events and/or Target Follow-up Time
Description
Calculate the Analysis Time Based on a Target Number of Events and/or Target Follow-up Time
Usage
calc_study_duration(
study_time,
observed_time,
event_indicator,
target_events = NULL,
target_follow_up = NULL
)
Arguments
study_time |
Vector of study times (accrual time + observed time) |
observed_time |
Vector of observed times (event time or censoring time) |
event_indicator |
Vector of boolean values (TRUE/FALSE or 1/0) indicating if the observed time value is an event or censoring time |
target_events |
Target number of events, where the analysis time is
determined once this number of events is reached. Default is |
target_follow_up |
Target follow-up for each participant, where the
analysis time is determined once each participant in the risk set is
followed up for this amount of time (i.e., minimum follow-up time). Default
is |
Details
This function calculates the analysis time for a study with a
time-to-event endpoint for which the target number of events
(target_events
) and/or target follow-up time (target_follow_up
) are
specified. If only target_events
is specified, the analysis will occur
at the time when the target number of events has been reached. If only
target_follow_up
is specified, the analysis will occur once the
last-enrolled participant who is still in the risk set has been followed up
for this amount of time. If both target_events
and target_follow_up
are
specified, the analysis time will be based on whichever occurs first.
Value
Time of analysis
Examples
library(dplyr)
# Determining analysis time by reaching a target number of events
ex_tte_df |> mutate(
analysis_time = calc_study_duration(study_time = total_time, observed_time = y,
event_indicator = event, target_events = 30)
)
# Determining analysis time by a target follow-up time
ex_tte_df |> mutate(
analysis_time = calc_study_duration(study_time = total_time, observed_time = y,
event_indicator = event, target_follow_up = 12)
)
# Or use both (whichever happens first)
ex_tte_df |> mutate(
analysis_time = calc_study_duration(study_time = total_time, observed_time = y,
event_indicator = event,
target_events = 30, target_follow_up = 12)
)