Get date at which an event count is reached

Usage

get_cut_date_by_event(x, event)

Arguments

x: A time-to-event dataset, for example, generated by sim_pw_surv().
event: Event count at which dataset is to be cut off for analysis.

Value

A numeric value with the cte from the input dataset at which the targeted event count is reached, or if the final event count is never reached, the final cte at which an event occurs.

Examples

library(dplyr)
#> 
#> Attaching package: ‘dplyr’
#> The following objects are masked from ‘package:stats’:
#> 
#>     filter, lag
#> The following objects are masked from ‘package:base’:
#> 
#>     intersect, setdiff, setequal, union

# Use default enrollment and calendar cut date
# for 50 events in the "Positive" stratum
x <- sim_pw_surv(
  n = 200,
  stratum = data.frame(
    stratum = c("Positive", "Negative"),
    p = c(.5, .5)
  ),
  fail_rate = data.frame(
    stratum = rep(c("Positive", "Negative"), 2),
    period = rep(1, 4),
    treatment = c(rep("control", 2), rep("experimental", 2)),
    duration = rep(1, 4),
    rate = log(2) / c(6, 9, 9, 12)
  ),
  dropout_rate = data.frame(
    stratum = rep(c("Positive", "Negative"), 2),
    period = rep(1, 4),
    treatment = c(rep("control", 2), rep("experimental", 2)),
    duration = rep(1, 4),
    rate = rep(.001, 4)
  )
)

d <- get_cut_date_by_event(x |> filter(stratum == "Positive"), event = 50)

y <- cut_data_by_date(x, cut_date = d)
table(y$stratum, y$event)
#>           
#>             0  1
#>   Negative 49 45
#>   Positive 37 50