Generate Sample Goodness-of-Follow-Up Data

Produces a reproducible data frame suitable for testing and demonstrating hv_followup(). Operation dates are drawn uniformly over the study period; death and non-fatal event times are simulated from exponential distributions and censored at each patient's potential follow-up. The deads column approximates active/systematic death ascertainment by restricting to deaths within 90% of the potential follow-up window, mirroring the distinction between dead and deads in the legacy tp.dp.gfup.R template.

Usage

sample_goodness_followup_data(
  n = 300,
  origin_year = 1990,
  study_start = as.Date("1990-01-01"),
  study_end = as.Date("2019-12-31"),
  close_date = as.Date("2021-08-06"),
  death_rate = 0.05,
  event_rate = 0.08,
  seed = 42L
)

Arguments

n

Integer number of patients to simulate. Default 300.

origin_year

Integer calendar year corresponding to zero in iv_opyrs. Default 1990.

study_start, study_end

Date (or coercible string) defining the operation date window.

close_date

Date (or coercible string) for the follow-up closing date. Must be >= study_end.

death_rate

Annual hazard for death (exponential model). Default 0.05 (median survival ~14 years).

event_rate

Annual hazard for the non-fatal event (exponential model). Default 0.08 (median time-to-event ~9 years).

seed

Integer random seed for reproducibility. Default 42.

Value

A data frame with columns:

iv_opyrs

Years from origin_year to operation date.

iv_dead

Follow-up years to death or censoring.

dead

Logical — all-source death indicator.

iv_event

Follow-up years to non-fatal event or censoring.

ev_event

Logical — non-fatal event indicator.

deads

Logical — active/systematic death indicator (subset of dead).

Details

The column names match the defaults of hv_followup(): iv_opyrs, iv_dead, dead. The event-panel columns (iv_event, ev_event, deads) are included so callers can pass event_col, event_time_col, and death_for_event_col directly.

Examples

dta <- sample_goodness_followup_data()
head(dta)
#>   iv_opyrs iv_dead  dead iv_event ev_event deads
#> 1  29.5694  2.0261 FALSE   2.0261    FALSE FALSE
#> 2   6.4834  6.9027  TRUE   4.0813     TRUE  TRUE
#> 3  14.4342  5.4468  TRUE   5.4468    FALSE  TRUE
#> 4  25.4324  6.1630 FALSE   0.6137     TRUE FALSE
#> 5   3.4251 13.1369  TRUE   6.9232     TRUE  TRUE
#> 6  24.1620  7.4334 FALSE   7.4334    FALSE FALSE

# Death panel
gf <- hv_followup(dta)
plot(gf) +
  ggplot2::scale_color_manual(
    values = c("Alive" = "blue", "Dead" = "red"), name = NULL
  ) +
  ggplot2::scale_shape_manual(values = c(1, 4), name = NULL) +
  ggplot2::labs(x = "Operation Date", y = "Follow-up (years)")


# Event panel
gf2 <- hv_followup(dta, event_col = "ev_event",
                      event_time_col = "iv_event",
                      death_for_event_col = "deads")
plot(gf2, type = "event") +
  ggplot2::scale_color_manual(
    values = c("No event" = "blue", "Non-fatal event" = "green3",
               "Death" = "red"),
    name   = NULL
  ) +
  ggplot2::scale_shape_manual(values = c(1, 2, 4), name = NULL) +
  ggplot2::labs(x = "Operation Date", y = "Follow-up (years)")