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Graft survival times of 1761 adult liver transplant recipients, with the cause of graft failure (Collett, 2023, Example 12.1).

Usage

liver

Format

A data frame with 1761 rows and 7 variables:

patient

Patient number (1-1761).

age

Age of the patient in years.

gender

Gender: 1 = male, 2 = female.

disease

Primary liver disease: 1 = primary biliary cirrhosis (PBC), 2 = primary sclerosing cholangitis (PSC), 3 = alcoholic liver disease (ALD).

time

Time from transplantation to graft failure, death or last follow-up, in days.

status

Event indicator: 1 = graft failure or death, 0 = right-censored.

cof

Cause of graft failure: 0 = functioning graft (censored), 1 = rejection, 2 = thrombosis, 3 = recurrent disease, 4 = other.

Source

Collett, D. (2023) Modelling Survival Data in Medical Research, 4th ed. Chapman & Hall/CRC, Example 12.1 (Table 12.1). Data from the UK Transplant Registry.

Details

The patients had a first elective transplant with an organ from a deceased donor between January 2000 and December 2010 and were followed up to the end of 2012. In the book there are 261 graft failures among the 1761 patients, and an additional 211 patients die with a functioning graft; the failure times of the latter group are censored at death. In the distributed file status is 1 for 265 patients while cof is non-zero for 260, so the two indicators are not perfectly consistent.

The data are the main illustration of competing risks: the cumulative incidence of each cause of graft failure, cause-specific hazard models and the subdistribution approach (Examples 12.1-12.6). See liver_wait for the waiting-list data from the same registry.

Aliases

The data set is available under the aliases d12.1, d12.2, d12.3, d12.4, d12.5, d12.6; dX.Y is the alias for the data set used in Example X.Y of Collett (2023). See dataset_by_exercise for the complete index.

Examples

# Collett (2023), Chapter 17 style -----------------------------------
# Examples 12.1-12.6: cumulative incidence by cause of graft failure
# (cof: 1 = rejection, 2 = thrombosis, 3 = recurrent disease, 4 = other)
ci <- cmprsk::cuminc(liver$time, liver$cof, liver$disease)
plot(ci, curvlab = c("PBC", "PSC", "ALD"), xlab = "Time (days)")


# A Fine-Gray model for one cause of failure (cause 2, thrombosis)
cmprsk::crr(
  liver$time, liver$cof,
  cov1 = as.matrix(liver[c("age", "gender")]),
  failcode = 2
)
#> convergence:  TRUE 
#> coefficients:
#>     age  gender 
#> -0.0253  0.1652 
#> standard errors:
#> [1] 0.01024 0.23530
#> two-sided p-values:
#>    age gender 
#>  0.013  0.480 

# Modern tools --------------------------------------------------------
if (requireNamespace("tidycmprsk", quietly = TRUE)) {
  tidycmprsk::cuminc(survival::Surv(time, factor(cof)) ~ disease, data = liver)
  tidycmprsk::crr(
    survival::Surv(time, factor(cof)) ~ age + gender,
    data = liver, failcode = "2"
  )
}
#> 
#> ── crr() ───────────────────────────────────────────────────────────────────────
#> • Call survival::Surv(time, factor(cof)) ~ age + gender
#> • Failure type of interest "2"
#> 
#> Variable   Coef     SE      HR     95% CI       p-value    
#> age        -0.025   0.010   0.98   0.96, 1.0    0.013      
#> gender     0.165    0.235   1.18   0.74, 1.87   0.48